Private costs associated with abdominal aortic aneurysm screening: the importance of private travel and time costs

Transcription

1 62 Journal of Medi<:al Sceening 1995;2:62-66 Papers Private costs associated with abdominal aortic aneurysm screening: the importance of private travel and time costs Stirling Bryan, Martin Buxton, Mike McKenna, Hilary Ashton, Alan Scott Health Economics Research Group, BruneI University, Uxbridge, Middlesex UB8 3PH, United Kingdom S Bryan, research fellow M Buxton, professor M McKenna, research fellow Scott Research Unit, St Richard's Hospital, Chichester, West Sussex, P019 4SE, United Kingdom Hilary Ashton, research coordinator Alan Scott, consultant surgeon Correspondence to: Mr Bryan. Accepted for publication 26 April 1995 Abstract Objectives - To assess the importance of the private costs incurredbypatientswhen making a judgment on the economics of screening for abdominal aortic aneurysm (AAA), and to explore the variation in such costs depending on screening location. Setting - A district general hospital and general practitioner surgeries. Methods - Four hundred and ninety nine consecutive subjects attending for AAA screening completed a questionnaire askingabout travelarrangements for the journey to and from the clinic, the distance travelled, the time taken, the mode of transport, and any out-of-pocket expenses incurred. In addition, at the clinic each subject was asked what activities they had forgone in attending the clinic. Time was valued differently depending on whether work or leisure activities were forgone. The total private cost for each attender was calculated and comparison was made between attenders at hospital and at general practice. Results - A significantly greater proportion of subjects were accompanied when attending hospital than when attending general practitioner (GP) surgeries. Most attenders travelled by car, but the journey time was significantly longer for those visiting hospital. The expected total private cost associated with attendance for AAA screening was Attendance at GP surgeries had a lower private cost ( 4.21) than attendance at hospital ( 6.87). Only 7'3% of all men surveyed, and 6'5% ofall companions, would have been taking part in some form ofpaid occupation if they had not attended for screening. Conclusion - Despite the fact that most attenders for AAA screening will be retired, the associated private costs are appreciable and should be considered in assessing the economics ofsuch screening programmes. The level of private costs varied depending onthelocationofscreening: clinics held at GP practices had lower private costs than those held at hospital. (Journal ofmedical Screening 1995;2:62-66) Key words: abdominal aortic aneurysm; economics; patient costs. Several studies of the economics of abdominal aortic aneurysm (AAA) screening have now been published.r" many of which have been based on a synthesis of data from a variety of sources. Screening for AAA has never been the subject of a definitive clinical trial, though a pilot randomised controlled trial is currently being undertaken in the United Kingdom.?" and some have argued that a definitive trial is now desired. 9 There is no clear consensus in the published literature on the relative costs and benefits associated with AAA screening: some authors argue strongly in favour of such a screening programme'<" while others argue that the benefits would be limited.:" None of the economic analyses has considered the issue ofprivate costs incurred by screening anenders. The largest part of the resource cost of care providedby the National Health Service (NHS) in the United Kingdom tends to fall on the health service. However, patients frequently incur out-of-pocket costs when they consume health care as a result of expenditure on such things as travel, child care, and home helps. Patients' involvement in health care also requires time to be devoted to travelling, waiting at the clinic, and the consultation itself. Therefore patients, inevitably, forgo activities that are of value to themselves and to society. Some private costs, such as the out-of-pocket expenses incurred by consumers ofhealth care, are of particular importance because they may act as a deterrent to the uptake of health care in certain situations. Such barriers might be most evident for preventive care, such as screening programmes, as the patient has no immediate symptoms ofillness. Thus a negative relation might be expected between the level of direct private costs and the uptake of screening programmes, other things being equal.

2 Private com of abdominal aortic aneurysm screening The private costs associated with other health care screening programmes, such as screening for breast cancer and for diabetic retinopathy, have been explored. 11l-l2 This paper presents data on private costs incurred by men, and their companions where appropriate, when attending for AAA screening. The aim was to consider the importance of such costs when making a judgment on the economics of AAA screening, and to explore the extent to which private costs varied depending on the location of screening. An investigation of the extent to which private costs acted as a barrier to the uptake of screening was outside the scope of this study. Methods For a pilot randornised trial of AAA screening the costs incurred by those being screened and their companions, where relevant, in attending AAA screening clinics were assessed. A survey technique was adopted. Some ofthose surveyed attended screening clinics in a hospital (St Richard's Hospital, Chichester, United Kingdom), and the remainder attended clinics at local general practice (GP) surgeries. All screening attenders were men aged between 65 and 74. This group was selected for screening because their prevalence of AAA is thought to be high, and elective repair was considered to be a realistic option. Assessment of the private costs was based on information provided by 499 screening attenders, who were asked to complete a short questionnaire at the end of their visit before leaving the hospital or surgery. The sample comprised 239 consecutive screening attenders at St Richard's Hospital and 260 consecutive screening attenders at local GP surgeries. Thus a comparison can be made of the private costs incurred by patients attending screening at hospital and those incurred by patients visiting their GP surgery for screening. Data were collected on the travel arrangements made by men and their companions for the journeys to and from the screening clinic. Details of the distance travelled, the mode of transport used and, where appropriate, the out-of-pocket expenses were also obtained. These data allowed travel costs to be estimated. For travel by train or bus the return fare was used, and for travel by private car the travel cost was obtained from the journey distance in miles multiplied by an average cost per mile, allowing for fixed costs, depreciation, and running costs." The companion's travel costs were also included in the total, but only when the companions themselves had no appointment at the hospital or GP surgery. The questionnaire was also used to obtain information about the time required for the journey to and from the clinic, the time spent at the clinic itself(both waiting time and screening time), and the activities forgone by the man and his companion in attending the clinic. Time is a valued resource and data on forgone activities were used to evaluate the travel and clinic attendance time. When work time had been given up to attend the clinic this was Table 1 Location before and after screening 63 All GP Hospital attenders attenders attenders Before Home 467 (95) 238 (92) 229 (98) Work 17 ( 3) 14 ( 5) 3 ( 1) Other 8 ( 2) 6 ( 2) 2 ( 1) After Home 423 (88) 229 (89) 194 (85) Work 15 ( 3) 8 ( 3) 7 ( 3) Other 45 ( 9) 19 ( 7) 26 (II) valued using average hourly pay rates for individuals over 60, increased to account for employer's costs." This valuation method was used regardless of whether the man or the employer actually incurred the cost as the study aimed at estimating total private costs. A narrower focus on costs incurred by patients would have been appropriate if, for example, the study had been investigating barriers to the uptake of screening. The hourly pay rates used were 7.43 for men and 6.15 for women (1994 price base). In this study, however, an assumption was made that all the companions were female. Non-working time was valued using guidelines generated for use in appraisals of transport projects." A constant value per hour is recommended, no matter to whom it applies, and thus a value on non-working time of 2.38 per hour (1994 price base) was used in this study. A comparison of private costs, the principal modes of transport used in the journey to and from the clinic, and the proportion of men who were accompanied at the clinic was made between screening clinics held at hospital and those held locally at GP practices. Statistical comparison was made using 95% confidence intervals for differences between means and proportions, as appropriate, for the two unpaired cases." Results All screening attenders who were asked to provide information on private costs completed a questionnaire. Thus data were available for 499 screening attenders: 239 had attended screening in a hospital and 260 in a GP practice setting. Table 1 shows where the screening attenders travelled from to attend the clinic and where they went after screening. Not surprisingly, most of these men were not working and travelled from and returned to their home. Table 2 shows how many of those attending screening were accompanied. A significantly greater proportion of those attending hospital than of those attending GP surgeries came with a companion (95% confidence interval for difference between proportions to -0'112). Table 2 Yes No Proportion of men accompanied All attenders 147 (30) 340 (70) GP auenders 53 (21) 200 (79) Hospital attenders 94 (40) 140 (60)

3 64 Bryan, Buxton, McKenna, Ashton, Scott Table 5 Table 6 Table 7 Table 3 Total time (minutes) spent at the screening clinic (excluding travelling time) Table 4 Setting Forgone activities (men and their companions) Screening clinic private costs: time- Travel Both men and their companions. AU GP Hospital attenders attenders attenders Mean SD 11' Median Q3-QI AJlanende~ 1 46 GP attenders 1 12 Hospital attenders 1 83 Expected time costs per man Clinic Principal mode 0/ transport used in journey to OP's surgery or hospital Total time (minutes) required/or return journey (all modes of transport) Total ' The mean length oftime spent by the patient at the screening clinic, excluding travelling time but including waiting time, was 29 9 minutes for all clinics (table 3). This figure includes the time waited by patients who arrived well before their scheduled appointment time. Although the mean time was similar for clinics held at a GP surgery (31,2 minutes) and those held at hospital (28'5 minutes), a small but significant difference was found (95% confidence interval for difference between means 0'776 to 4'64). The time spent at the clinic by both the screening attender and his companion was estimated All auenders GP attenders Hospital attenders 95% CIfor differences No (%) No (%) between proportions Private car 369 (75) 182 (71) 187 (79) -0,163 to -0,0110 Bus 22 ( 4) 5 ( 2) 17 ( 7) -0,0897 to -0,0156 Foot 80 (16) 58 (22) 22 ( 9) to Other 23 ( 5) 13 ( 5) 10 ( 4) -0,0290 to AU GP Hospital auenders attenders attenders Mean SD Median Q3-QI % CI for differences betueen meam -16,0 to -9,13 AU auenders GP attenders Hospital attenders No (%) No (%) Men Paid occupation 34 ( 7) 21 ( 9) 13 ( 6) Carer 12 ( 3) 3 ( I) 9 ( 4) Other 422 (90) 218 (90) 204 (90) Companions Paid occupation 9 ( 6) 2 ( 4) 7 ( 8) Carer 5 ( 4) I ( 2) 4 ( 5) Other 125 (90) 49 (94) 76 (87) to have a value of 1.71 per attender. This estimate was similar for climes held at GP surgeries ( 1.70) and those held at hospital ( 1.72). The costs associated with waiting time are slightly higher for the hospital based clinics, despite the fact that hospital clinics were actually shorter, because a higher proportion of those attending hospital screening clinics were accompanied. Table 4 shows the time costs associated with attending screening clinics. By far the most popular mode of transport used in travelling to and from the screening clinic was the private car (table 5). Almost 80% of all hospital attenders travelled by car, whereas the proportion using a car to travel to the GP surgery was slightly lower at about 70% - a significant difference (95% confidence interval for difference between proportions -0,163 to -0'011). A significantly greater proportion of hospital attenders than GP attenders used public transport, whereas many more GP attenders walked to and from the clinic. Table 6 shows that return journey times took an overall mean of25 7 minutes, and that journeys to and from hospital were significantly longer than journeys to and from GP surgeries (95% confidence interval for difference between means -16'0 to -9'13). The mean cost associated with travel for AAA screening, regardless of location and exeluding the value on time, was 2.30 for the return journey. The expected travel cost for a hospital screening attender was 3.32 and for a GP screening attender was only Table 4 shows that visits to hospital, with their longer journey times and greater number of companions, had a higher time cost ( 1.83) than visits to the GP surgery ( 1.12). When data on time costs (table 4) were combined with data on travel costs, the expected total private cost associated with attendance for AAA screening was calculated to be Attendance at hospital was associated with a higher expected total private cost ( 6.87) than attendance at the GP surgery ( 4.21). Only 7% of all men in the survey and 6% of their companions indicated that they would have been taking part in some form of paid occupation if they had not been invited to attend for AAA screening (table 7). Of the screening attenders visiting a GP surgery for the clinic, 9% would otherwise have been involved in paid occupation, whereas only 6% of attenders at hospital gave up paid occupation to be screened. This difference is not significant (95% confidence interval for difference between proportions -0,0174 to 0'0759). Similarly, the proportion of companions forgoing paid occupation to accompany the screening attender did not differ significantly between Table 8 Arrangements made to be absent from work Men attending screening Companions All attenders No (%) GPartenders No (%) Hospital attenders AU auenders GP attenders Hospital attenders No (%) No (%) No (%) Hours rearranged Time off without loss of pay Time off with loss of pay Other 3 (10) II (37) 6 (20) 10 (33) 3 (16) 6 (32) 6 (32) 4 (21) o ( 0) 3 (38) o ( 0) 3 (50) 5 (45) I (13) o ( 0) I (17) o ( 0) 2 (25) I (50) I (17) 6 (55) 2 (25) I (50) I (17)

4 Private costs of abdominal aortic aneurysm screening GP and hospital settings (95% confidence interval for difference between proportions -0'119 to 0'0355). Table 8 shows the arrangements made by screening attenders and their companions who were in paid occupation. Of the 34 men who indicated that they would otherwise have been in paid occupation, 30 provided details of the arrangements they had made at work to take time off to attend the clinic. Only six men and two companions lost money as a result of attending the screening clinic. Thus the mean total time required for all aspects of the clinic attendance was 55 6 minutes per attender. The larger part of this time was taken up in the clinic itself (29'9 minutes), and the mean time required for travel was 25 7 minutes. The mean private cost associated with the time required for screening attendance was estimated to be Time costs are clearly the dominant element of the total private cost; the mean costs incurred in travel were only 2.30 per attender. Therefore, the expected total private cost per attender was estimated to be This estimate includes the costs incurred by companions where the screening attender was accompanied. Ifthe companion's costs were excluded then the expected total private cost per attender would be Discussion Economic evaluation of alternative health care programmes aims at identifying those that provide the maximum benefit from the limited resources available. The perspective a given evaluation takes will determine which costs and which benefits should be included in the analysis. The broadest perspective and that most consistent with traditional welfare economics is that of the whole of society. Such a perspective defines benefits broadly in terms of patient utility and not narrowly in terms of health alone. It indicates that without an assessment of the resource costs incurred by patients and employers an economic assessment would be incomplete." However, if a narrower perspective of, for example, the health care sector is adopted, then the analysis will focus on the best use of the health care budget and would not consider opportunity costs incurred elsewhere in the economy. I? In such situations the assessment ofbenefits might appropriately be restricted to health alone and the assessment ofcosts might justifiably exclude all costs not falling on the health care budget. Such partial perspectives, however, inevitably contain arbitrary dividing lines, and costs will be considered only if they happen to fall within a particular budget. Data were collected from a relatively large sample of consecutive AM screening attenders, and thus the findings from this survey should be broadly representative of screening attenders at Chichester. The results indicate that the private costs associated with an AM screening programme are appreciable and, if included in an economic analysis, may affect its conclusions. For example, in the analysis presented by Law et ai, 6 the inclusion ofprivate costs at the level indicated here would have increased the total net cost of the screening programme by about This would represent an increase in programme cost of about 8%. The results confirm our prior expectation that indirect costs - that is, costs associated with productivity losses resulting from time off work, are of little relevance to the economics of AM screening. As most attenders had retired, any productivity losses resulting from attendance at screening were small. Fewer than 7% of screening attenders would otherwise have been taking part in paid employment, and, in fact, only just over 1% of all screening attenders, and a similar proportion of companions, actually lost money as a result of attending the screening programme rather than work. Whether or not there was a productivity loss covered by the employer cannot easily be judged. Comparison was made of the private costs incurred by men who attended screening at hospital with those incurred by men who attended their local GP surgery. Patients were not randomly allocated to receive care in one setting or the other and, thus, one has to be careful in attributing differences between groups to the difference in setting. The decision on the allocation of patients to a particular screening setting was made solely on the basis of the area in which the patient lived. Patients living in Worthing were screened at their GP practice and those living in other districts surrounding Chichester were screened at hospital. Both groups of patients were selected by the criteria of sex and age only, and both groups were approached in exactly the same manner. The data reported here indicate that the proportion of men who gave up paid employment to attend for screening were similar in both patient groups. The results indicate that the location of the screening clinic was an important factor in determining the level of private costs. Not surprisingly, private costs were greater for clinics held at hospital. A similar result was found in an economic evaluation ofalternative strategies for diabetic retinopathy screening. 18 The higher private costs for hospital settings are a function of higher travel costs and longer journey times for hospital clinics as might be expected, but also a function ofmore men being accompanied to clinics at hospital. One interpretation of this finding is that more of the men invited to hospital were anxious and, therefore, wished for the support ofa companion. However, another possible interpretation is that the visit to hospital for a screening appointment was combined with other social or domestic activities. Collin J. The value of screening for abdominal aortic aneurysms by ultrasound. In: Greenhalgh RM, Marrick JA, eds, The cawe and management of aneurysms. London: Saunders, Russell JGB. Is screening for abdominal aortic aneurysm wonhwhile? Clin RadioI1990;41: Harris PL. Reducing the mortality from abdominal aortic aneurysms: the need for a national screening programme. BM] 1992;305: Mason JM, Wakeman AP, Drummond MF, Crump BJ. Population screening for abdominal aortic aneurysm: do the benefits ourweigh the costs? ] Public Health Med 1993; 15;

5 66 Bryan, Buxton, McKenna, Ashton, SCOll 5 Frame PS, Fryback DG, Patterson C. Screening for abdominal aortic aneurysm in men ages 60 to 80 years. A cost-effectiveness analysis. Ann Intern Med 1993;119: Law MR, Morris J, Wald NJ. Screening for abdominal aortic aneurysms. Journal ofmedical Screening 1994;1: Khoo DE, Ashton H, Scott RAP. Is screening once at age 65 an effective method for detection of abdominal aortic aneurysms? Journal ofmedical Screening 1994;1: Scott RAP, Ashton H, Kay DN. Abdominal aortic aneurysm in 4237 screened patients: prevalence, development and management over 6 years. BrJ Su'!: 1991;78: Bryan S, Buxton MJ, Scott RAP, Ashton HA. Population screening for abdominal aortic aneurysm (letter), J Public Health Med 1994;16: Bryan S, Brown J, Warren R. Mammography screening: an incremental cost-effectiveness analysis of two view venus one view procedures in London. J Epidemiol Community Health 1995;49: Sculpher MJ, Buxton MJ, Ferguson BA, Spiegelhalter DJ, Kirby AJ. Screening for diabetic retinopathy: a cost-effect- iveness analysis of alternative modalities and strategies. Health Economics 1992;1: Sculpher MJ, Buxton MJ. The private costs incurred when patients visit screening clinics: the cases of screening for breast caru;er and for diabetic retinopathy. Uxbridge: Brunei Universiry, (HERG discussion paper 10.) 13 Automobile Association. Motoring costs. London: AA Technical Services, Department of Employment. New earnings survey: part E. London: HMSO, Department of Transport. Values for journey time savings and accident prevention. London: Department of Transport, GardenerMJ, Altman DG. Statistics with confidence. London: BMJ, Gerard K, Mooney G. QALY league tables: handle with care. Health Economics 1993;2: Health Economics Research Group. Diabetic retinopathy screening project: special medical development project at Exeter, Oxford and Sheffield. Final report. Uxbridge: Brunel University, 1990.