JBI Library of Systematic Reviews JBI ; 10(35):

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1 The incidence, prevalence and contributing associated with the occurrence of medication errors for children and adults in the community setting: a systematic review Kim Sears, RN, PhD 1 Amanda Ross-White, MLIS, AHIP 2 Christina M. Godfrey, RN PhD 3 1. Assistant Professor and Deputy Director, Queen's University The Queen's Joanna Briggs Collaboration for Patient Safety: a collaborating centre of the Joanna Briggs Institute, Queen's University, Kingston, Ontario, Canada (QJBC) School of Nursing, Queen's University 92 Barrie Street Kingston, Ontario K7L 3N6 Canada 2. Health Sciences Librarian, Nursing, Queen s University, The Queen's Joanna Briggs Collaboration for Patient Safety: a collaborating centre of the Joanna Briggs Institute, Queen's University, Kingston, Ontario, Canada (QJBC) 3. Assistant Professor and Methodologist/Deputy Director, The Queen's Joanna Briggs Collaboration for Patient Safety: a collaborating centre of the Joanna Briggs Institute, Queen's University, Kingston, Ontario, Canada (QJBC) Corresponding Author: Kim Sears, kim.sears@queensu.ca Executive Summary Background Medication delivery is a complex process which provides numerous opportunities for error occurrence. While the community environment presents a unique potential for medication errors, to date, an exploration of these errors had not been conducted. Sears et al. The incidence, prevalence and contributing associated with the occurrence of medication errors for children and adults in the community setting the authors 2012 Page 2350

2 Objectives The overall objective of the review was to identify the incidence, prevalence and contributing associated with the occurrence of medication errors for children and adults in the community setting. Inclusion criteria Types of participants Studies involving children and adults from the community setting. Focus of the review In this review we considered studies that evaluate the incidence, prevalence and contributing associated with the occurrence of medication errors in the community setting for both children and adults. Types of studies In this review we considered any randomised controlled trials, non-randomised controlled trials, controlled before and after studies, other designs such as cohort, case control studies and descriptive studies. Search strategy Papers in English between the years were searched in various scholarly databases, including: CINAHL, Medline, Mosby s Nursing Consult, PsycINFO, and Web of Science. Methodological quality Full papers were assessed for methodological quality independently by two reviewers using critical appraisal checklists from the Joanna Briggs Institute. Data collection Details of each study included in the review were extracted using an adaptation of the standardised data extraction forms developed by the Joanna Briggs Institute. Sears et al. The incidence, prevalence and contributing associated with the occurrence of medication errors for children and adults in the community setting the authors 2012 Page 2351

3 Data synthesis Meta-analysis was not possible due to methodological and statistical heterogeneity of the included studies. Hence study findings are presented in narrative form. Results Twenty-one studies were included in the final review. Thirteen studies examined either incidence or prevalence. Ten studies identified contributing and five studies reported the frequency of errors. Conclusions This study provides the first systematic review of medication error occurrence for children and adults in the community. Evidence emerging for this review highlighted the incomparability within the included studies and current research and thus the inability to make recommendations to advance the science. Implications for practice Commonly reported causal were dosing errors, misreading prescriptions and calculation errors. Therefore, it is recommended that adequate education is provided to ensure that healthcare providers are well equipped to perform the tasks involved in medication delivery. Further recommendations include: 1) ensure workloads within the community setting support safe and reasonable assignments; 2) reinforce communication protocols between healthcare providers and patients regarding medication delivery; and 3) separate and identify look alike and sound alike medications. Implications for research For the science in this area to advance, there is a need for standardization on how outcomes are identified and measured within each stage. Therefore, it is recommended that common conceptualizations for these terms be established or agreed upon and a valid tracking system is in place in the community. Keywords: medication errors, community, paediatrics, pediatrics, child, adult, Sears et al. The incidence, prevalence and contributing associated with the occurrence of medication errors for children and adults in the community setting the authors 2012 Page 2352

4 Background Medication safety is a key issue in the quality and patient safety movement. Medication delivery is complex in all areas of health care; safe delivery of medications to children, however, presents additional challenges and opportunities for error. Paediatric medication errors have been identified as the most frequent type of medical error involving children. 1;2 In children, especially those under the age of twelve, are treated as therapeutic orphans since suitable formulations of many drugs are based solely on adult requirements. 3-5 Carleton and Smith noted that, until recently, it was assumed that children were small adults ; thus, adult dosages were adjusted to account for the smaller body mass, with the assumption that clinical results would mimic those of adults. 5 Another common concern for paediatric medication administration is off-label prescribing as many drug companies have not received the appropriate approval for paediatric formulations. 6 In fact, 75% of licensed pharmaceuticals in North America have never been tested on children, yet they are utilised in paediatric hospital settings without adequate guidelines for safety and efficacy. 7 Children present unique demands in regards to medication ordering, dispensing, administering and monitoring as they often require weight-based dosing calculations, a situation further complicated by a lack of standardised paediatric easy-to-use dosage formulations. 4;8 Further, the process of dosing is complicated by the interchange of milligrams and micrograms. 6 Delivering medications to children requires that an individual dose incorporates comprehension of the age, weight and surface area of the child. 9 As well, children s medications are dispensed in multiple preparations, including drops, elixirs, chewable tablets, capsules and infusions. 10 Tenfold medication errors are more likely to occur among children as a result of non-suspicious small volumes 1 posing severe consequences in paediatrics. 6 Recently, it has been shown that a host of biological, developmental and behavioural in children affect the safety and effectiveness of pharmaceuticals being used. These internal present an enormous concern for children whose condition is critical as they may have a limited ability to buffer the harmful effects of medications. 11 Further, very young children may be placed at higher risk as they may not be able to verbalise their experiences, feelings and subjective reactions to the medications. 2 A retrospective search of two large medication data bases in the United States showed the risk of harm from medication errors in adults to be 13%, compared to 31 % in children. 12 The researchers concluded that the paediatric population appeared to be more vulnerable to adverse outcomes from medication errors than were adults. Fortescue et al., 11 studied 1,020 paediatric patients at two academic centres during a six week period and found that 120 (19.5%) of the medication errors were classified as potentially harmful. Another group at high risk for serious complications in regards to medication errors is those individuals over the age of 60 years. The US Federal Drug Agency (FDA) noted that more than half of fatal medication errors occurred in people 60 years or over. 13 Another risk factor for this group is the aspect of Sears et al. The incidence, prevalence and contributing associated with the occurrence of medication errors for children and adults in the community setting the authors 2012 Page 2353

5 polypharmacy. The issue of polypharmacy has been identified as a contributing risk factor to increased morbidity and mortality. 14 Furthermore, the odds for potentially inappropriate medication prescribing are higher for individuals taking multiple drugs. 15 In the United States, it is estimated that at least one medication error occurs per day per adult hospitalised patient. 16 This high rate of error demonstrates the complexity of the delivery of a medication. The delivery of a single medication involves steps, each of which increases the risk for error. 17 In comparison to the adult population, Kaushal et al., 2 examined the rates of paediatric medication errors as well as actual and potential adverse drug events (ADEs) and then compared the findings with those of adults. The researchers reviewed 10,778 medication orders and found 616 medication errors; equating to 5.7 per 100 orders or 55 per 100 admissions. The potential for ADEs was three times higher in the paediatric population than in the adult patient population. 2 Although research into medication errors in hospital has been conducted, the safe delivery and consumption of medications in communities remains largely unstudied, despite the high volume of healthcare encounters. (For example, over 422 million prescriptions dispensed per year in Canada). 18 While the nature of underreporting makes it impossible to determine the exact number of incidents per year, it is estimated that in 2009 the number of medication incidents in community pharmacies in Canada was approximately 7 million. 19 The lack of research into medication errors in the community not only places patients and healthcare systems at risk, but also represents a lost opportunity for learning from errors and taking steps as an organization (e.g., workflow/ dispensing changes) to reduce the likelihood of them occurring again. Furthermore, it represents a large financial burden on the healthcare system. Canada, the cost of preventable drug-related morbidity and mortality in older adults was estimated at C$11 billion in In the United States, a conservative estimate of US$3.5 billion annually has been attributed to medication errors. In Australia, inappropriate medication use, including errors, has been shown to cost about A$380 million per year in the public health system alone. Although efforts have been made to make medication safety a priority, 20 and in spite of research attempts to determine underlying causes of medication incidents, and error reduction strategies, 22;24 little is known about the safety of medication practices in the community worldwide. In Medication safety in the home environment poses unique issues that are unaddressed by research into the institutional care environment. In particular, home care workers have identified concerns about the use of medication by someone other than the patient (either inadvertently through medication diversion or intentionally through the illegal trafficking of medication); accidental access to medication by persons other than the patient or primary caregiver; and both intentional incorrect administration such as overmedicating as well as unintentional incorrect administration. 25 An honest assessment of medication safety is needed to identify processes and organizational infrastructures that may place individuals at risk. Sears et al. The incidence, prevalence and contributing associated with the occurrence of medication errors for children and adults in the community setting the authors 2012 Page 2354

6 Although research on medication safety has increased in the last few years, research in the area of medication errors in the community remains limited. A study from the United Kingdom reported an incidence rate of 22 near misses and 4 medication errors for every 10,000 items dispensed. 21 An observational study from the United States had a comparable incidence rate. 22 Furthermore, research indicates that 28% of all emergency visits occur because of a drug related problem, defined as an inappropriate prescription, an adverse drug reaction and/or a drug to drug interaction, with 24% of these resulting in a hospital admission. 26 A search of the JBI Library of Systematic Reviews, Cochrane Library, Medline and CINAHL found no existing systematic review on this topic. There have been studies that examined medication errors at one stage in the medication delivery process or a specific drug class or patient population but they were primarily related to the hospital environment. Review question/objective The objective of this systematic review was to determine the evidence on the incidence, prevalence and contributing related to medication errors in the community setting. The specific review question was: What are the incidence, prevalence and contributing associated with the occurrence of medication errors for children and adults in the community setting? Inclusion Criteria Types of participants In this review we considered studies that include adults and children living in the community that have experienced a medication error. For the purposes of this review, the term living in the community includes living at home/ residential homes. Focus of the Review In this review we considered studies that evaluate the incidence, prevalence and contributing associated with the occurrence of medication errors in the community setting for both children and adults. Types of studies In this review we considered any randomised controlled trials, non-randomised controlled trials, controlled before and after studies, other designs such as cohort, case control studies and descriptive studies. Sears et al. The incidence, prevalence and contributing associated with the occurrence of medication errors for children and adults in the community setting the authors 2012 Page 2355

7 Search strategy The search strategy aimed to find both published and unpublished studies in English between the years We used a three-step search strategy beginning with an initial limited search of MEDLINE and CINAHL. We analysed the text words contained in the title and abstract of relevant articles, and the index terms used to describe these articles. A second search using all identified keywords and index terms was undertaken across all included databases. Thirdly, the reference list of all identified reports and articles was searched for additional studies. The databases searched included: Medline, CINAHL, Embase, GlobalHealth, Ageline, Cochrane, AMED, and PsycInfo Web of Science, Proquest Dissertations. The search for unpublished studies included: Institute for Safe Medication Practice, Canadian Institute for Health Information, Canadian Patient Safety Institute and the Canadian Health Services Research Foundation. For the MEDLINE search strategy see Appendix I. Details on additional search strategies in other databases could be provided by authors on request. All studies identified during searching were assessed for relevance to the review based on information provided in the title, abstract, and subject terms. Full papers were retrieved for studies that satisfied the inclusion criteria, or if the relevance could not be determined from the metadata. Studies identified from reference list searches of included studies were assessed for relevance based on the title Method of the Review Assessment of methodological quality Papers selected for retrieval were assessed for methodological quality by two independent reviewers using standardised critical appraisal instruments from the Joanna Briggs Institute (JBI) (see Appendix II). Any disagreements that arose between the reviewers were resolved through discussion, or with a third reviewer. Data extraction We initially planned to use the JBI MAStARI Data Extraction Forms for Experimental and Observational Studies (Appendix III). However, when the data was examined in more detail it became clear that we required more detail than was available in these forms. Hence, the data was extracted using an Sears et al. The incidence, prevalence and contributing associated with the occurrence of medication errors for children and adults in the community setting the authors 2012 Page 2356

8 adaptation of these standardised data extraction tools (Appendix IV). Our adapted forms included specific details about the interventions, such as, how medication errors were classified and measured, stage when the medication error occurred, and the most common medication involved in errors. Data synthesis Meta-analysis was not possible due to methodological and statistical heterogeneity of the included studies. Hence study findings are presented in narrative form. The data was analysed into the following categories: a. The incidence and /or prevalence of medication errors b. Stage at which the error occurred a. Prescribing b. Dispensing c. Administration c.contributing Factors for medication error occurrence a) Special Considerations a. Issues relevant to the community setting b. Paediatric Results c. Results for adults over 60 years d. Frequency of medication errors e. Medications involved in medication errors Definitions or classifications of medication errors were obtained from each study to assess for variation in perspectives on the concept of medication errors. The contributing were analysed using the Conceptual Framework for the International Classification for Patient Safety proposed by the World Health Organization (WHO). 27 WHO defines Contributing Factors/Hazards as the circumstances, actions or influences which are thought to have played a part in the origin or development of an incident or to increase the risk of an incident. Examples are human such as behavior, performance or communication; system such as work environment; and external beyond the control of the organisation, such as the natural environment Sears et al. The incidence, prevalence and contributing associated with the occurrence of medication errors for children and adults in the community setting the authors 2012 Page 2357

9 or legislative policy. More than one contributing factor and/or hazard is typically involved in a single patient safety incident. 27,p.11 The WHO framework is a multi-layered conceptualisation and the contributing segment comprises up to a maximum of five levels. We classified the contributing identified in this review using the first two levels. Review Results Description of studies A total of 2,831 citations were located by the search strategy (Figure 1). Of this set, citations were removed or discarded for the following reasons: 698 were duplicates, 2006 were off-topic, and 108 did not meet inclusion criteria. Following critical appraisal, no studies were excluded based on not meeting the quality appraisal criteria. Twenty-one studies were included in this systematic review. Sears et al. The incidence, prevalence and contributing associated with the occurrence of medication errors for children and adults in the community setting the authors 2012 Page 2358

10 Figure 1: Search Decision Flow Diagram Medline 866 CINAHL 192 Embase 696 Ageline 159 AMED 14 PsycInfo 88 Sociological Abstracts, Social Sciences Abstracts and IBSS 67 Cochrane (complete) 98 GlobalHealth 26 Web of Science 594 Proquest Dissertations 31 Hand Search / Grey Literature 2 Total Number of Articles Retrieved from Searching 2831 Duplicates Removed 698 Number of Articles Reviewed at Metadata Level (Title/Abstract) 2135 Number of Articles Excluded at Metadata Level: Not on Topic 2006 Number of Articles Reviewed in Full Text 129 Number of Articles Excluded After Reviewing Full Text: Not Meeting Inclusion Criteria 108 Final Number of Articles reviewed for Critical Appraisal 21 Number of Articles Excluded: Not Meeting Critical Appraisal Criteria 0 Final Number of Articles Included in Review 21 Sears et al. The incidence, prevalence and contributing associated with the occurrence of medication errors for children and adults in the community setting the authors 2012 Page 2359

11 Of the 21 studies that met the inclusion criteria for this study, according to the location of the primary author, 11 studies were from the United States, four studies were from the United Kingdom, 21;39-41 four studies from Australia, one from Denmark, 46 and one from India. 47 (Appendix V, Table 1). All of the studies in this review were descriptive in nature. Seven studies explored data that was collected within the time frame of their study (prospective method), 21;30;35;36;38;41;42 and six studies explored data that had previously been conducted (retrospective method). 28;33;34;40;43;46 Research designs identified included, four cross sectional observational, 29;31;32;47 two observational, 37;44 one analytic case series (series of case reports), 45 and one mixed methods. 39 In most studies, participants were not randomly selected. However, five studies used random sampling to select their samples. 29;39;40;46;47 Chen and colleagues 40 used a 3% random sample (n=1135) of their population. Pandey et al., 47 selected the pharmacies that would be surveyed using a random number table. Flynn et al., 29 and Knudsen et al., 46 used a random sample of community chain pharmacies. Barber et al., 39 randomly selected 256 residents from 55 care homes in the United Kingdom. Thirteen studies examined either incidence or prevalence. Ten studies identified contributing and four studies reported the frequency of errors. Methodological quality Given the paucity of research in this area, a cut-off point of five was established for each JBI checklist to ensure that there were a sufficient number of studies to review but the strength of the methodological quality was maintained. Research in this area is typically not randomized. Reduced levels of methodological rigour were evident as studies did not address how they would deal with participants that withdrew from the study and the lack of reporting of adequate follow-up of patients. However, no studies were excluded based on critical appraisal. The studies were descriptive and met the JBI level of evidence at the level of three. Number of studies found Number selected for retrieval Sears et al. The incidence, prevalence and contributing associated with the occurrence of medication errors for children and adults in the community setting the authors 2012 Page 2360

12 Results Definition of errors The studies used a variety of definitions for the concept of medication error and examined errors within different contexts. In their study Pandey et al., 47 defined a medication error as medications prescribed that were not listed in the World Health Organization (WHO) list of essential medicines for children (first list, October 2007). Chen et al., 40 defined medication errors within the context of contraindicated drug combinations and compiled a list of contraindicated drug combinations based according to established references. Flynn et al., 29 defined a dispensing error as a filled prescription that contained one or more differences from the prescriber s written order. In two studies dispensing errors were defined as incidents that were detected after the patient had taken possession of the medication. 21;41 Young et al., defined medication administration errors as any difference between what the patient received or was supposed to receive and what the prescriber intended in the original order. 31,p.1200 Li et al., 32 classified a medication error as a variation in the dose from the normal appropriate dosage for that medication. Taylor et al., 44 defined a therapeutic error as an unintentional deviation from a proper therapeutic regime that results in the wrong dose, incorrect route of administration, administration to the wrong person, or administration of the wrong substance. Hansen defined medication errors as preventable events that had the potential to cause/lead to or actually caused/led to inappropriate medication use or patient harm. 38 Definitions of harm When mentioned, the concept of harm varied across studies. For Barber et al., 39 the mean potential harm from prescribing, monitoring, administration and dispensing errors and each error was individually assessed by an expert using a validated 10-point scale (0=no harm; 10=death); their mean score was taken as the harm score for that error. Walsh and colleagues 28 had physician reviewers independently place each possible error into one of the following four categories: (1) a medication error causing injury to the patient; (2) a medication error that had the potential to cause injury but did not injure the patient; (3) a medication error that did not have the potential to cause harm; or (4) not a medication error (exclusion). Kuo et al., 30 used the harm severity categories of the US Pharmacopeia National Coordinating Council for Medication Error Reporting and Prevention to code harm. Young used a group of reviewers and determined for each medication error the potential to cause harm by assigning a score of 1 (important) to 5 (not important) and the likelihood of causing harm by assigning a score of 1 (very likely) to 5 (very unlikely). 31 Methods to capture errors A variety of methods were used for error detection. Prescribing stage examination of prescriptions for appropriateness of prescribed medications for children; 47 and chart review. 40 Dispensing stage use of a data collection form and/or checklist. 21;29;41 Administration stage observation and chart review; 31 questionnaire; 32 self-reported caregiver data from a poison control centre for children. 44 In the studies that Sears et al. The incidence, prevalence and contributing associated with the occurrence of medication errors for children and adults in the community setting the authors 2012 Page 2361

13 looked beyond one stage, methods included a coding system and data collection form; 46 a web-based tool; 38 and chart review. 28;30;39 Fourteen studies (67%) used a method of data collection that included self-report. 21;30;32-36;38;41-46 studies used data from poison control centres. 33;34;43-45 Five Incidence results In this review we used the definition of incidence as new cases within a specified condition over a specified period of time by the number at risk of being a new case. 48 Although sometimes loosely expressed simply as the number of new cases during some time period, it is better expressed as a proportion or a rate with a denominator. 49 Eight studies provided incidence rates. However, none of the studies actually provided their definition of incidence. The synthesis of this section was complicated by the variety of contexts and the use of different denominators to establish incidence rates. Incidence rates ranged from a set of total errors over 10,000 medications dispensed 21;41;46 to total errors over 100,000 cases medications administered, 44 and from 100 clinic visits 28 to 100 beds 38 to 1000 years 40 (Appendix VI, Table 2). Prevalence results The definition of prevalence used for this review was the proportion of a population having a particular condition at a given point in time. 48 Five studies provided prevalence estimates or percentages we assumed to be prevalence estimates given the context of the data. However, none of the studies actually provided their definition of prevalence. Furthermore, how prevalence was calculated differed across studies and prohibited the synthesis of results. Studies located in this review provided the following range of prevalence estimates: number of errors per total number of prescriptions; 29;30 number of various medication errors per number of medications given; 39 number of administration errors per number of medications given multiplied by 100; 31;32 and number of various medication errors per number of medications given multiplied by (Appendix VII, Table 3). Stage of error Prescribing errors The incidence of prescribing errors was identified by four studies. 38;40;46;47 Pandey et al., 47 identified the prescribing error rate by prescriber profile and found the range of errors to be from 0.92 SD 0.63 to 2.11 SD Chen et al., 40 identified an incidence rate of 1.9 per 1000 patient years (95% CI 1.5,2.3) or 4.3 per 1000 patients being concurrently prescribed two or more incompatible drugs per year (95% CI 3.2, 5.4). Knudsen et al., 46 noted that 23/10,000 prescriptions required correction by a pharmacist. Hansen et al., 38 found prescribing errors accounted for a mean of 0.8 errors per 100 beds (95% CI ). Sears et al. The incidence, prevalence and contributing associated with the occurrence of medication errors for children and adults in the community setting the authors 2012 Page 2362

14 Two studies provided prevalence estimates of prescribing errors. 30;38;39 Barber et al., 39 found that 100/256 residents (39.1%, 95% CI ) had one or more prescribing errors, totaling 153/356 prescription errors. They also noted the prescribing error rate as 8.3% (95% CI ). Kuo et al., 30 found the error rate to be 126/178 (70%). Dispensing errors Six studies examined dispensing errors in community pharmacies or by community pharmacists. 21;29;30;39;41;46 Three studies reported the dispensing incidence over 10,000 medications. 21;41;46 Notably, these studies demonstrated that there was a higher risk for a near miss occurring rather than an actual error ( near miss was classified as an error detected prior to reaching the patient). For prescription corrections Knudsen et al., 46 found the error rate to be 23/10,000 prescriptions; for dispensing errors 1/10,000 and for near misses 2/10,000. (Knudsen). Ashcroft et al., 21 found on average, for every 10,000 items dispensed, there are around 22 near misses and 4 dispensing errors (280 incidents, or 84.8%). Chua et al., 41 noted that for every 10,000 items dispensed there are 56 dispensing errors or near misses with 95% CI of 49-62; near misses 247/51,357 (0.48%). These results show that near misses occurred six times more often than dispensing errors. Of the three studies that identified the prevalence of prescribing errors, Flynn et al., 29 examined 100 prescriptions dispensed, 22 had one or more deviation from the physician s written order, giving a 22% dispensing error rate. Kuo et al., 30 found the rate of dispensing errors to be 7%. In Barber et al. s 39 examination of the prevalence of dispensing errors in 94 residents they found 187 dispensing errors (36.7%, 95% CI ), with a mean of 0.73 (95% CI ) dispensing errors per resident. Dispensing error rate by opportunity for error was 9.8% (95% CI ). Medication administration errors Seven studies examined administration errors ;38;39;44;46 Three examined the incidence of administration errors. Taylor et al., 44 reported the incidence of medication administration errors in a population of children. From January 2006 and March 2007 they identified 491 cases of which incorrect and double dosage accounted for 279 (56.8%, 95% CI 52.3, 61.2) and 128 (26.1%, 95% CI 22.3, 30.2) cases, respectively. Knudsen et al., 46 found that for all of the errors identified in their study the rate of administration errors were 13.5%. Hansen et al., 38 found the mean for medication administration errors to be 12.1 errors per 100 beds (95% CI ). Four studies examined the prevalence of administration errors. Kuo et al., 30 reported the prevalence of medication administration errors as being 10%. Young et al., 31 described 4,866 observations per 510 residents, 1,373 errors were observed (28.2% error rate). Li et al., 32 mentioned 51% of patients received an inaccurate dose of medication, including 62% of patients given acetaminophen and 26% of patients Sears et al. The incidence, prevalence and contributing associated with the occurrence of medication errors for children and adults in the community setting the authors 2012 Page 2363

15 given ibuprofen. In the study by Barber et al., 39 they also examined the prevalence of administration errors and found that the mean potential harm from administration errors 2.1 and 2.0 (0=no harm, 10=death). Mean number of administration errors per resident 0.45% (95% CI ) and the prevalence of administration errors by opportunity for error 8.4% (95% CI ). Contributing Ten studies 21;28;32;35;36;39;40;44-46 discussed the contributing to the medication errors they investigated. The first level of the framework groups the into the following six categories (Appendix VIII, Table 4): Staff, patient, work/environment, organisational/service, external and other. At the second level, both staff and patient categories incorporate the following seven : Cognitive, performance, behaviour, communication, pathophysiologic disease related, emotional and social. Staff - Cognitive - the most frequent causal factor reported was a lack of knowledge or confusion about the medication, mentioned eight times. (Appendix IX, Table 5) Staff - Performance these refer to skill based errors and the most frequently reported causal factor were dosing errors, misreading prescriptions and calculation errors mentioned 13 times (Appendix X, Table 6). In their study on pharmacists assessment of dispensing errors, Bond and Raehl 36 report that membership in pharmacy organisations for 60% of their respondents was associated with a reduced risk of dispensing errors (risk score of errors rs = , p=0.005 ). The amount of time pharmacists spent providing clinical services (risk score of errors rs = , p<0.001) was also related to the risk of dispensing errors. Staff - Behaviour the most frequently reported causal were fatigue, carelessness or lack of concentration mentioned seven times (Appendix XI, Table 7). In the study by Szeinbach et al., 35 age was seen as a factor amongst pharmacists with mean number of perceived dispensing errors (mean=1.94, SD=1.90) significantly lower for younger than older pharmacists (mean=3.42, SD=4.12). Staff - Communication - poor communication or lack of communication between doctor and patient or between staff, patient and carers were reported as causative by three studies (Appendix XII, Table 8). Staff - Emotional - Bond and Raehl 36 report that one of the strongest predictors of dispensing errors for pharmacists related to the pharmacists overall level of satisfaction (Appendix XIII, Sears et al. The incidence, prevalence and contributing associated with the occurrence of medication errors for children and adults in the community setting the authors 2012 Page 2364

16 Table 9). Once this level increased, the risk of dispensing errors decreased (risk score of errors rs=-0.422, p<0.001). Patient - the most commonly reported causal were confusion or lack of awareness of medications in the cognitive category, mentioned three times, and dosing errors in the performance category also mentioned three times (Appendix XIV, Table 10). Work/environment - the second level for work/environment category comprises: Physical environment /infrastructure, remote/long distance from service, environmental risk assessment/safety/evaluation and current code/specification/regulation (Appendix XV, Table 11). All environment reported by studies related to the physical environment/ infrastructure category of the framework. Causal included care homes that were hot, airless, poorly lit and short of space and pharmacy environments that were busy, pressured, noisy and fraught with frequent interruptions and distractions. In their study of pharmacists assessment of dispensing errors Bond and Raehl 36 report that based on the assessment of the practice site, mail service pharmacies were seen to have the highest risk or medication errors (1.85 ± 1.32). Traditional chain pharmacies had second highest risk score for dispensing errors (1.66 ± 1.18), whereas mass merchandise chain (1.30 ± 1.08) and grocery store chain pharmacies (1.30 ± 0.96), had risk scores below mean for all pharmacists (1.33 ± 1.12). Organisational/service - at the second level, organisational are further divided into: Protocols/policies/procedures/processes, organisational decisions/culture, organisation of teams and resources/workload (Appendix XVI, Table 12). Resources/workload was the most frequently populated category and five of the eight studies report being very busy and being distracted as causal for medication errors. Bond and Raehl 36 report that time/prescription ranged from 1 every minutes in home health care to 1 every 1.26 minutes in mail service pharmacies. This variable (risk score of errors rs=0.285, p<0.001) was one of strongest predictors of risk of dispensing errors. 36,p.617 External - at the second level, external comprise the following three categories: Natural environment, products, technology and infrastructure and services, systems and policies (Appendix XVII, Table 13). All were categorised under products/technology and infrastructure. Issues related to the similar looking medications, similar looking containers/ packaging and similar drug names were the most frequently reported (seven times). The first level category other was not populated and is therefore not represented in any of the subsequent tables. Sears et al. The incidence, prevalence and contributing associated with the occurrence of medication errors for children and adults in the community setting the authors 2012 Page 2365

17 Special Considerations Issue relevant to the community setting Individuals face different risk for medication errors in the community setting. Pharmacists have different work environments and many more distractions to contend with that may place them at risk for dispensing errors. In community settings administration is primarily the responsibility of the individual or caregiver and therefore dependent upon many variables such as distraction, confusion, fatigue, level of knowledge, resources and capacity. Environments themselves may be an obstacle because of poor lighting, lack of space to store medications, and medication cabinets with a range of medications perhaps belonging to several individuals and potentially expired medications. As in the hospital setting, similar packaging and similar medication name combinations are also a confusing factor that individuals may have to contend with. These could contribute to an increase in the risk of medication errors in the community setting. Paediatric results A specific focus was applied to children in eight studies 28;32-34;37;43;44;47 (Appendix XVIII, Table 14). Within this category studies looked at a range of issues such as: place of occurrence, age, dosage errors, time of medication error, route of medication error, number and type of medication involved and the administrator. There appeared to be consensus on younger children being more at risk for errors, with Taylor 44 finding the majority of children were three years or less, Li 32 narrowing that down even further to report their finding that infants < 1 year old were more likely to receive an inaccurate dose of medication (RR1.40, P < 0.04, 95% CI = ), Tzimenatos and Bond 34 noted that significant errors disproportionately occurred in children less than 1 year (107/238 cases, 45%), and Crouch, 33 found that more than half of the exposures occurred in children 12months. There was consensus in four of the eight studies that medication errors were associated with home medication use, 28;33;34;44 with Taylor 44 establishing that 98.2% of all errors they investigated occurred in the home and Crouch 33 identifying the home as the most common site 92.7%. Dosing was mentioned as a primary contributor to the medication error. Excessive dosing was identified 34 as well as double dosing 43;44 and the inaccuracy of the tools used to administer the dose 33;37 (for example a teaspoon). Results for adults over 60 years There were no studies that examined the risk as applicable only to adults over 60 years but with compounding scenarios of complex chronic conditions and resultant polypharmacy, plus the potential for Sears et al. The incidence, prevalence and contributing associated with the occurrence of medication errors for children and adults in the community setting the authors 2012 Page 2366

18 decreased cognitive and functional capacity 50 there is a strong possibility that older populations living in community settings may be at risk for medication errors. Frequency of medication errors Tzimenatos and Bond, 34 Crouch et al., 33 and Shah and Barker 43 all used data from the National Poison Control Centres databases for the years or Taylor et al., 44 used data from the Victoria Poisons Information Centre. As this information is collected voluntarily, accurate incidence rates cannot be determined. Several articles provided information about frequency, the number of errors occurring within the study period. Nau et al., 42 report that in a survey of 920 University of Michigan employees and retirees, 168 had experience a medication error and 193 knew a family member or friend who had experienced an error. As the survey asked whether an error had occurred sometime in the past, no specific study period could be determined and no incidence rate was recorded. Similarly, because it is unknown how many family members or friends might be included in the survey responses, no prevalence can be determined. Simon 37 reported that out of 41 families recruited to demonstrate the administration of albuterol, nine gave an improper dose. Seven intended to give the correct dose, but erred in the measurement of the dose. Tzimenatos and Bond 34 provided a frequency rate of 272 cases of therapeutic error in children less than six years reported to poison control centres in Of these 164 occurred in the home or community setting. Prevalence and incidence could not be determined because it is unknown how many errors might not have been reported to a poison control centre and the number of potential exposures to over the counter medications is unknown. Tzimenatos and Bond 34 also note that over the counter medications are implicated in a large number of errors. Crouch et al., 33 also use data from US poison control centres to determine 3,914 ten-fold dosing errors that occurred in children under six years from , of which 3,698 errors occurred outside a health care facility. Shah and Barker 43 provide a frequency of 1,191,038 cases of medication errors between 2000 and 2005 of which 92.4% (1,077,065 cases) occurred outside a health care facility. Taylor et al., 44 identified 708 cases of medication errors from their sample of 97 community residential units and 611 home residents. Medications involved in medication errors Several articles mentioned the medications most frequently associated with errors, either by class (Appendix XIX, Table 15) or by drug name (Appendix XX, Table 16). The five most common drug classes associated with errors are analgesics (including NSAIDs), cough and cold preparations, cardiovascular (including antihypertensive) medications, antihistamines and antimicrobials. The five most common drug names associated with errors are Cimetidine, Metoclopramide, Lorazepam, Warfarin, and Insulin. Sears et al. The incidence, prevalence and contributing associated with the occurrence of medication errors for children and adults in the community setting the authors 2012 Page 2367

19 Discussion There is limited research on medication error occurrence in the community and the extent of risk is not well understood. In advancing the science in the area of medication errors within this context, it is important to examine how errors occur within the entire medication delivery process. The lack of standardisation has led to a lack of comparability across sites and studies which in turn, have reduced the advancement of research in this area. Therefore, prior to any further research being conducted it is imperative that a standard terminology be adopted in relation to medication errors. Although some of the most important variables to investigate have been identified, 51 such as the specific medication involved, the mode of delivery, the stage of error occurrence, key issues within that stage, the level of harm and the nature of the error, because of the variation at the primary research level, we lack the evidence at the synthesis level. Synthesis of the studies included in this review was hampered by: a) variation in both conceptualisation and methodology. Some studies measured medication errors across the different stages of delivery, itemised the medications involved, or reported the frequency of errors. While some studies extracted data from poison control centres others used chart reviews or examined prescriptions. b) Nature of error reporting. When examining medication errors (at any stage), research typically relies upon self-report. However, this means it is virtually impossible to attain a precise number of errors due to the predominance of underreporting that occurs. Of the 21 studies included in this review, 14 studies (67%) relied on self-reported data including data from poison control centres, clinician and /or caregiver selfreport. Incidence and prevalence The synthesis of data related to incidence and prevalence was complicated by the variety of contexts in which the errors occurred, and the use of different denominators to establish their results. For example, incidence rates ranged from a set of total errors over 10,000 medications dispensed to total errors over 100,000 cases of medications administered, and from 100 clinic visits to 100 beds. Prevalence estimates ranged from the number of errors per total number of prescriptions, number of various medication errors per number of medications given, number of administration errors per number of medications given multiplied by 100, and number of various medication errors per number of medications given multiplied by 100. Given this variability there is no common basis upon which to determine overall rates or prevalence estimates. Research in this area will not advance until common conceptualisations for these terms have been established or agreed upon. Contributing The WHO Conceptual Framework for the International Classification for Patient Safety 27 provided a comprehensive structure to examine the multitude of contributing associated with medication Sears et al. The incidence, prevalence and contributing associated with the occurrence of medication errors for children and adults in the community setting the authors 2012 Page 2368

20 errors. In this review we examined medication errors in the community and within this context identified both level of satisfaction as well as workload and environment issues as contributing to errors performed by pharmacists. For other healthcare providers the most commonly reported causal were dosing errors, misreading prescriptions and calculation errors which were mentioned thirteen times. At the patient level, confusion or lack of awareness of medications were the most commonly reported causal errors, clearly indicating the need for greater clarification when healthcare providers transfer knowledge to patients. Workload was also seen to be important as a source of causal associated with medication errors. External that are beyond control but influence all healthcare providers as well as the patient generated the second most frequently reported causal, those being similar looking medications, similar looking containers/ packaging and similar drug names, all reported seven times. These findings are substantiated by the Institute of Medicine: 52,p.275 Confusion caused by similar drug names accounts for up to 25 percent of all errors reported to the Medication Error Reporting Program operated cooperatively by U.S. Pharmacopeia (USP) and the Institute for Safe Medication Practices (ISMP). In addition, labeling and packaging issues were cited as the cause of 33 percent of errors, including 30 percent of fatalities, reported to the program. Workload emerged as an important contributing factor for error occurrence. This is consistent with previous studies. In a doctoral thesis Sears 51 identified the following contributing for the occurrence of paediatric medication administration errors (in descending order of significance): (a) workload, (b) distraction and (c) ineffective communication. It is postulated the many of the same contribute to medication error occurrence at the three stages of medication delivery. Issue relevant to the community setting Although, Individuals face various different risk for medication errors in the community setting, many are similar to the hospital setting. For example, the impact of environmental and issues of medication packaging and labeling affect both settings. However, in the hospital setting there is a better system for medication error tracking. In a recent study by Sears et al., 53 it was demonstrated that in an international study (n=9944) of medication errors, approximately 4 out of every 5 self-reported medication error occurred in the community setting. Paediatric findings Eight studies examined medication errors for children in the community setting. Of this set, five studies 28;32;34;43;44 identified that the administration stage was a high risk for error occurrence. The administration stage is an area that requires further support related especially to dosing. Five studies identified dosing as a primary contributor to the medication error. 33;34;37;43;44 Sears et al. The incidence, prevalence and contributing associated with the occurrence of medication errors for children and adults in the community setting the authors 2012 Page 2369