Estimating the client costs of addiction treatment: first findings from the client drug abuse treatment cost analysis program (Client DATCAP)

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Estimating the client costs of addiction treatment: first findings from the client drug abuse treatment cost analysis program (Client DATCAP) Helena J. Salome´ a, Michael T. French b,*, Michael Miller c, A. Thomas McLellan d a

Health Services Research Center, University of Miami, Miami, FL 33136, USA Department of Health Administration and Policy, Medical University of South Carolina, Health Administration and Policy, 19 Hagood Avenue-Suite 408, P.O. Box 250807, Charleston, SC 29425, USA c Department of Epidemiology and Public Health, The Village Treatment Center, University of Miami, Miami, FL 33136, USA d Treatment Research Institute, University of Pennsylvania, Philadelphia, PA 19106, USA b

Received 24 March 2002; received in revised form 3 April 2003; accepted 4 April 2003

Abstract The costs of addiction treatment services are an important determinant of the cost-effectiveness of a program, and therefore, of relevance to addiction treatment providers, insurance companies and, patients. Several methods have been developed to estimate the costs of substance abuse treatment services. One such method is the drug abuse treatment cost analysis program (DATCAP), which collects resource use and cost data from the treatment program perspective and has been used in numerous published economic evaluation studies. However, no single widely-used, standardized instrument is currently available to estimate costs specifically incurred by clients in treatment. In response to that need, this article introduces the Client DATCAP and presents process, surveyspecific, and quantitative findings from a Pilot Study to estimate the client costs of attending outpatient and inpatient treatment. The preliminary findings suggest that the self-administered Client DATCAP is a feasible and practical instrument for estimating costs incurred by clients in treatment, with completion time amounting to less than 10 min. Furthermore, client costs had a considerable range across respondents, with time costs consistently accounting for the largest cost component. Findings from the Pilot Study led to the development and release of edition 2 of the outpatient and inpatient modules of the Client DATCAP. # 2003 Elsevier Science Ireland Ltd. All rights reserved. Keywords: DATCAP; Client DATCAP; Treatment cost; Economic evaluation

1. Introduction In the current climate of exponentially increasing health care costs, economic evaluations of treatment are frequently performed to assist payers and providers in deciding how to efficiently allocate public and private treatment resources. In the area of substance abuse treatment, several rigorous economic evaluations of addiction treatment have recently been conducted, measuring a broad range of treatment outcomes and costs (e.g. Barnett, 1999; Barnett and Swindle, 1997; Barnett et al., 2001; French et al., 2000, 2002a,b, 2002;

* Corresponding author. E-mail address: [email protected] (M.T. French).

Flynn et al., 1999; Hartz et al., 1999; Long et al., 1998; Weisner et al., 2000; Zarkin et al., 2001). In the process, measures from economic and non-economic evaluation instruments have sometimes been translated into estimates of costs and benefits of care to clients, programs, and society (e.g. addiction severity index (ASI), treatment services review (TSR), drug abuse treatment cost analysis program (DATCAP)). Benefit analyses of addiction treatment, as a separate evaluation or a component of a full economic assessment, generally take account of relevant and quantifiable outcomes from a societal perspective. Such outcomes might include reductions in criminal activity, mental and physical health care utilization, consumption of addictive substances, and improvements in employment and income (e.g. French et al., 1996,

03765-8716/03/$ - see front matter # 2003 Elsevier Science Ireland Ltd. All rights reserved. doi:10.1016/S0376-8716(03)00133-9

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2000; French and Zarkin, 1992; French et al., 2002a,b; Holder et al., 2000; Rajkumar and French, 1997). Cost studies of addiction treatment, on the other hand, are often restricted to a program or payer perspective (e.g. Anderson et al., 1998; French et al., 1997; French and McGeary, 1997; Salome´ and French, 2001) and thus fail to identify and quantify the important direct and indirect costs specifically incurred by the clients in treatment. Client costs in studies of medical treatment could include the opportunity cost1 of time spent in treatment (i.e. employment income and leisure time forgone), travel expenditures, cash or in-kind payments for treatment, and other miscellaneous expenditures, such as dependent care. The main objective of the present study was to develop a method for measuring costs specifically incurred by clients in substance abuse treatment. The data collection instrument developed for that purpose is the Client DATCAP (French, 2002a,b), a supplemental module to the original Program DATCAP (French, 2001). This manuscript will outline the implementation efforts and preliminary findings from the first Pilot Study of the Client DATCAP that was recently carried out on two samples, totaling 77 adult clients enrolled in inpatient and outpatient substance abuse treatment programs in Miami, Florida. The principal aims were to (1) test the feasibility and client acceptability of the instrument in both inpatient and outpatient treatment settings; (2) examine the range and magnitude of costs incurred by clients in treatment; and (3) determine the practicality of the instrument under (proctored) selfadministration.

2. The Client DATCAP Economic evaluations sometimes adopt dissimilar methodologies or estimation perspectives, making cross-program or longitudinal comparisons inaccurate or infeasible. In addition, some studies derive resource costs from program budgets, rather than applying the principle of economic or opportunity cost (French and McGeary, 1997; French, 2000; Salome´ and French, 2001). The Program DATCAP (French, 2001) was developed in the early 1990s to fill the need for a reliable, easy-to-use instrument for measuring program costs that would enable uniform and comparative measurement of the economic or opportunity cost of substance abuse treatment (e.g. French et al., 1994, 1 In general, economic or opportunity cost refers to the value of the next best alternative application of the action or resource. For the present analysis, the opportunity cost of time equates to the income received from employment or to the value of leisure time that the client has to forgo to attend treatment.

1996, 1997; French and McGeary, 1997; Salome´ and French, 2001; Roebuck et al., in press; http:// www.DATCAP.com). Resource use and cost categories in the DATCAP instrument include personnel, supplies and materials, contracted services, buildings and facilities, equipment, and other resources and costs borne by the program. The Program DATCAP, however, exclusively measures treatment costs incurred by the program. To broaden the instrument’s measurement perspective, a supplemental version of the DATCAP was recently designed that specifically measures the costs incurred by treatment clients. The resulting Client DATCAP serves as a companion instrument to the original Program DATCAP, using similar terminology and time frames. Due to the variations in costs incurred by clients at inpatient and outpatient treatment programs, separate modules were developed for each setting. The description of the Client DATCAP that follows relates to the Pilot Edition, the instrument that was initially developed to be used during the Pilot Study. Subsequently, based on the results of this Pilot Study and feedback from colleagues and anonymous reviewers for this journal, substantial changes have been implemented to both modules of the instrument. For a complete description of the changes to the Pilot Edition and the content of the current edition (Edition 2) (French, 2002a,b), please refer to Section 6. A copy of both editions can be obtained free of charge from the corresponding author or downloaded at http:// www.DATCAP.com. The Pilot Edition of Client DATCAP-I consisted of 17 open-ended, multiple-choice questions and was specifically designed to measure costs incurred by patients attending inpatient treatment (i.e. inpatient detoxification, short- and long-term residential, hospital inpatient, and therapeutic community modalities). The Pilot Edition of Client DATCAP-O had 25 questions and measured costs incurred by patients in outpatient treatment (i.e. outpatient detoxification, outpatient drug-free, methadone maintenance, day treatment, and intensive outpatient modalities). Questions on costs incurred by clients in either treatment setting were grouped into four categories. The first category applied to the opportunity cost of time spent in treatment, which is based largely on forgone employment income and leisure time. In the Pilot Study, time cost was expected to account for the largest share of total patient costs. The second category applied to any cash or in-kind payments clients make to attend treatment. In-kind payments are non-monetary contributions made by the client to the treatment program, such as donated time, supplies, and equipment. The third category included any other costs that the client incurred as a result of attending treatment, such as expenditures on dependent care, parking fees, or

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physical exams. The outpatient module had all of the above categories as well as a fourth category specifically measuring costs incurred by traveling back and forth to visit the program. Finally, the combined cost categories formed the total cost of treatment from the patient perspective. Total cost estimates can be calculated for a treatment visit or day (unit costs) or for the entire episode (incurred costs). In addition to questions related to resources contributed or sacrificed by clients in treatment, both modules also contained questions on the number of completed treatment visits/days to date and the frequency of treatment2. These items were used to convert the reported cost information into unit costs (i.e. per visit or per day) or into total costs incurred to date. Other procedural questions addressed number of visits to the program per week, distance and time traveled to the program, time spent at the program, treatment interference with work (outpatient only) and hours worked per week, and hourly rate of pay. The unit cost estimates were multiplied by the number of treatment visits/days completed to produce an estimate for the total cost of total treatment received. Finally, questions on age, marital status, gender, race, work history, educational background, and times in treatment provided a socio-demographic profile of the client sample and enabled further exploratory analyses of the cost data. The Pilot Edition of the Client DATCAP was carefully designed to enhance comprehension and accuracy while minimizing the burden on the client. Questions were straightforward, and clear directions guided the respondent through the instrument. The instrument was intended for self-administration, which introduces concerns of data validity and reliability. Although no published research has examined the validity of self-reported cost information, studies of selfreported data regarding addiction behaviors, such as drug use, generally show conflicting results. Maisto et al. (1990), who examined 14 studies on the reliability and validity of self-reported drug use, reported a high degree of variability in the validity of self-reported data both within and across studies. Darke (1998) reviewed the literature on the reliability and validity of self-reported drug use, crime, and HIV risk behavior among injecting drug users. These authors generally found good reliability and validity of these self-reported behaviors, 2 Both the DATCAP-O and DATCAP-I also contained a question about the number of expected future treatment visits/days. Although this information could be used to estimate the expected client costs of future treatment, the reliability of such an estimate would be uncertain, and it was, therefore, decided not to incorporate the responses about expected future treatment into the present cost estimates. Moreover, the questions on number of treatment visits or days received and expected were not retained in Edition 2 of the instrument.

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comparing them to biomarkers, criminal records, and collateral interviews. Some recent studies support this assessment, finding self-reported drug-use information to be quite accurate (e.g. Hersh et al., 1999; Weiss et al., 1998), while others have found substantial underreporting (Colon et al., 2002; Morral et al., 1999).

3. Pilot Study design During the Pilot Study of the Client DATCAP, both modules were administered to clients of The Village, a substance abuse treatment organization with various locations throughout southern Florida. Clients from inpatient and outpatient treatment programs were recruited from facilities in and around Miami. Client recruitment took place at the program location during several consecutive site visits by the research team. All clients were approached at the beginning or end of a treatment session. Each client present during the visit was given the option to participate in the Pilot Study. The instrument was self-administered, but two project coordinators were present to assist participants and to ensure compliance with the research protocol. All participation was strictly voluntary and confidential. No direct personal identifiers (e.g. name, social security number) were asked that could link the information to the respondent. Nevertheless, prior to the administration of the instrument, each participant was asked to sign a consent statement for release of information, which described the contents of the instrument, the nature and purpose of the research, and the data disclosure. It was the project coordinators’ responsibility to fully explain the research protocol and the consent form. To encourage research participation and improve data quality, respondents were offered $5 upon completion of the Client DATCAP as partial compensation for their time and effort. Several studies have shown a higher response rate for participants who receive an incentive (Martinez-Ebers, 1997; Shaw et al., 2001). A total of 50 clients were recruited to test the Client DATCAP-I, while 27 clients were recruited to test the Client DATCAP-O. The outpatient sample consisted of individuals in drug-free outpatient and intensive outpatient programs. Because recruitment was contingent on the number of patients enrolled in treatment at the time of administration, and because the Pilot Study budget was modest, sample sizes were relatively small3. 3 It must be remembered that the primary purpose of this Pilot Study was, as part of the process of instrument development, to evaluate the feasibility and practicality of the instrument (see McLellan et al., 1992, 1980). For this particular purpose, a large sample was not required.

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It is important to emphasize that only those patients on site at the time of survey administration were approached for recruitment into the study. In the case of outpatient treatment, the research team returned a second time to try to recruit those outpatient clients absent during the first visit. Due to the small sample sizes and the narrow purpose of this Pilot Study, the data analysis and reported findings were based on a distinction between non-specific inpatient and outpatient treatment only, without regard to particular modalities or other unique program and facility-type characteristics.

4. Methods As noted previously, the Pilot Edition of the Client DATCAP consisted of four primary cost categories: cash or in-kind payments, travel costs (outpatient only), time costs, and other (miscellaneous) costs. Furthermore, the instrument was structured to estimate unit costs (for one visit in the case of outpatient; for 1 day in the case of inpatient) as well as total incurred costs. Incurred costs pertain to the period between the start of treatment in the program and the day the Client DATCAP was administered. The following provides an overview of each cost item, its computation, and its economic relevance. The question numbers provided in brackets refer to the corresponding questions in the Pilot Edition of the Client DATCAP. Clients were asked to report cash or in-kind payments for a typical week in treatment. It was expected that clients would provide more accurate information for a short time frame than for the entire treatment episode. Weekly cash or in-kind payments (S12 in the Pilot Edition of the Client DATCAP) were summed across all items and then divided by the typical number of treatment visits per week (S13 , outpatient) or 7 days (inpatient) to calculate the average (or unit) cost per visit or per day. These estimated unit costs were then multiplied by the number of completed treatment visits (S9 , outpatient) or completed days in treatment (S9 , inpatient) to calculate the total incurred cash or in-kind payments. Other (miscellaneous) costs were calculated similarly, where S18 on the outpatient module and S13 on the inpatient module pertain to other costs. Travel costs represent the cost of traveling back and forth to the program for clients in outpatient treatment. The per visit travel cost was reported directly by the respondents (S17 , outpatient). Total incurred travel costs were obtained by multiplying the cost per visit by the number of completed treatment visits (S9 , outpatient). Time spent in treatment represents an opportunity cost of treatment attendance and theoretically can be

disaggregated into employment and leisure components. Employment cost represents the value of time forgone during which the client normally would have engaged in compensated labor and earned wages or a salary. Leisure cost represents the value of the lost ability to enjoy leisure activities while engaged in treatment (Garber et al., 1996). In other words, a cost is associated with the leisure time that the client cannot allocate freely. The opportunity cost of work time is traditionally valued at the individual’s prevailing rate of pay. Leisure time, however, is harder to value because individualspecific rates are not observable. In practice, estimates for the value of 1 h of leisure time may range from zero to the compensation for 1 h of overtime work (Drummond et al., 1997). The rates most often used are the normal rate of pay and the minimum wage. For clients in inpatient treatment, time cost was calculated for 16 h a day because it was assumed that the remaining 8 h of the day were spent sleeping. As sleeping occurs regardless of being in or out of treatment, these hours should not necessarily be considered as an opportunity cost to the client. For outpatient treatment, time cost applied to the hours spent in treatment as well as travel time. Employment costs were calculated for those clients with any employment history and based on the reported hourly wage. For inpatient treatment, employment costs were based on the reported number of hours worked per week. For outpatient treatment, employment costs were simply assigned for treatment and travel time, regardless of whether treatment interfered with employment. In the case of inpatient treatment, leisure costs were calculated for the remaining hours in treatment beyond the reported hours worked (up to 16 h in a given day). For outpatient treatment, leisure costs were calculated for total treatment and travel time when the client had no employment history. Calculations for this exercise were somewhat simplified as no distinction was made between leisure and labor time in terms of the hourly rate. For those reporting any employment history, both labor and leisure time were valued at the most recent hourly wage rate reported. For those without employment history both labor and leisure time were valued at the minimum wage rate ($5.15). To indicate whether the client had any employment history, a dichotomous measure d was created (based on questions S14 in DATCAP-I and S20 in DATCAP-O), with d/1 if ever employed and d/0 if never employed. Time cost per visit for the clients in outpatient treatment was then calculated by multiplying an hourly rate (w ) by the sum of the number of hours in treatment (S19 ) and the time spent traveling to the program (2 /S15 ), where w /S25 (i.e. hourly wage rate) if d/1 and w/ $5.15 (i.e. minimum wage rate) if d /0. Total time cost was equal

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to the cost per visit multiplied by the number of visits completed (S9 )4. As explained above, time costs for inpatient clients involved different calculations. More specifically, time cost per day of treatment was equal to 16 h multiplied by an hourly rate (w ), as defined above. Total time cost for inpatient clients was equal to the cost per day multiplied by the total number of treatment days completed (S9 ). Note that cost calculations from a partial sensitivity analysis of time costs are contained in Section 7. The total client cost per visit for outpatient clients and per day for inpatient clients was simply equal to the sum of the cost components presented above. As noted earlier, total incurred costs are the costs that the client sustained from the start of the program until the day the Client DATCAP was administered. For clients in outpatient treatment, these costs represented the sum of cash or in-kind payments, other (miscellaneous) costs, travel costs, and time costs. Total incurred costs for inpatient clients included cash or in-kind payments, other (miscellaneous) costs, and time costs.

5. Pilot Study results The results of this study are divided into three categories: process results, survey-specific results, and quantitative findings. Process results consist mainly of practical observations from the survey administration process. Survey-specific results identify strengths and limitations associated with survey design and content. Quantitative findings consist of summary statistics from analysis of the pilot data, including measures of central tendency for relevant demographics and cost data. 5.1. Process results The participation rate of the clients that were recruited for the Pilot Study was nearly 100%. From the outpatient sample, only two clients of those approached declined to participate (for unspecified reasons). None of the recruited inpatient clients declined to participate. No persuasion tactics other than the assurance of confidentiality and the small cash incentive ($5) were used to enhance participation.

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Prior to signing the informed consent agreement, some questions were raised by clients regarding potential consequences of participation. Most importantly, at least three clients required explicit reconfirmation of confidentiality. Project coordinators had to corroborate that no personal identifiers were collected and that no individual-level data would be made public or available to individuals outside the research team. Thus, despite the non-sensitive nature of the information collected, assurance of confidentiality might be an important condition for ensuring high participation rates. In general, participants, including those (N /16) who had not completed high school, had no problems understanding or completing the questions. One patient required assistance from the proctor in completing the instrument, and five patients (6.5%) asked for assistance with respect to the exact intent of a particular question. The average completion time amounted to less than the 10 min anticipated (approximate range: 5
/10 min). During completion of the Client DATCAP, a few questions and suggestions were raised by the respondents, some of which have led to amendments of the design and content of the Pilot Edition of the instrument. First, several respondents experienced a recall problem regarding the number of treatment visits/days they had attended to date (Question S9 ). Since the maximum reported number of visits/days attended was 270 visits for outpatient clients and 460 days for inpatient clients, this recall issue is legitimate. Similarly, the maximum number of future visits/days expected amounted to 400 visits for outpatient clients and 500 days for inpatient clients (Question S10 ). Close attention was paid to these forecasting difficulties, and it was decided that for future analyses the individual length-ofstay information would be directly obtained from program records instead of relying on patient forecasting or projections (for details please refer to Section 6). Second, several clients were uncertain about the exact number of miles they traveled to reach the treatment program (Question S14 in Client DATCAP-O). Note that this question was merely inserted to enable analysts to calculate travel costs in case the respondent failed to report travel expenditures (Question S17 ), but was not actually used for the present analysis. Also, mileage information could be important as a normalizing factor for travel costs or for those clients who use private transportation (e.g. personal car). 5.2. Survey-specific results

4

Note that when calculating the time cost for outpatient clients, question S22 on whether treatment interfered with employment of the respondent was not taken into consideration. Since labour time and leisure time were valued at the same rate, this information did not alter the cost calculations. Nevertheless, when adopting different rates for both time costs, those respondents who experience treatment interference should be distinguished from those who do not (please also refer to Section 7 for the presentation of a sensitivity analysis).

Survey-specific findings are based on a systematic quality assessment of the pilot data and should be viewed as less anecdotal or subjective than the process results discussed above. An overall review of these data indicates that some variables had more missing values and/or multiple response/bad data than others. First,

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seven out of 77 respondents (9%) did not answer the age question. It is likely that this result is more related to confidentiality concerns than to problems with question or survey design. Second, seven respondents (9%) did not answer the questions pertaining to treatment visits/days attended and anticipated. As discussed in Section 6, for future data collection and analyses, treatment length-of-stay information will be collected from program records instead of relying on patient recall. Third, most respondents (91%) left the direct cost variables (e.g. cash or in-kind payments and other costs) blank. As these questions did not specifically instruct the respondent to write zero, many individuals probably left the question unanswered in the case of zero costs. An instruction to write zero in case of no costs is included in Edition 2 of the instrument. To avoid a large number of missing observations in the Pilot Study dataset, a zero value was assumed for any blank answer. Finally, several questionnaires had bad or missing data for the questions related to treatment interference with work. Upon analysis, it was concluded that the survey design in this section was somewhat confusing, which may have contributed to the bad or missing data. Confidentiality concerns could be another cause, but appear unlikely in this area. In Edition 2 of the instrument, an attempt has been made to improve upon the design through better syntax and questionnaire instructions. 5.3. Quantitative results It is important to note that the primary aim of this study was to pilot-test both the feasibility of collecting cost information directly from clients in addiction treatment and the practicability of the methods. In light of those aims, summary statistics of the data collected were calculated primarily to evaluate the performance of the individual items of the instrument, not to generate representative cost estimates. Quantitative results consist of summary statistics for selected demographics and cost measures. Questions pertaining to client characteristics provide an important demographic profile of the client sample and enable multivariate analysis of how demographic characteristics affect client costs. Furthermore, client profiles permit more accurate cross-program analyses by controlling for demographic characteristics. As noted earlier, a few measures had missing data. With various measures employed in each of the cost calculations, complete data for all observations was imperative. Consequently, all missing data values (i.e. item non-response) were imputed using the hot-deck imputation procedure instead of assigning mean values. A hot-deck procedure finds for each non-respondent a matching respondent based on categorical variables that

are specified a priori and observed for both respondents (Rubin, 1987). Due to the small sample size and the small number of missing values for any particular measure (i.e. less than 11% of the full sample), hotdeck imputations were not run on matching observations selected a priori. It is believed that the improvements made in question design, questionnaire instructions, and quality control methods will reduce the number of missing data in future applications. An overview of the client characteristics of the Pilot Study samples is presented in Table 1. Sixty-three percent of the inpatient sample was male, compared with 48% of the outpatient sample. The average age for both samples was approximately 37 years, and about 20% of the clients were married. Of the outpatient sample, 44% was African American, 37% Hispanic, and 15% White. Of the inpatient sample, 54% was African American, 26% Hispanic, and 18% White. The average number of years of education for both samples amounted to nearly 12 years. Mean values (with selected standard deviations (S.D.s)) of treatment characteristics, including procedural measures, are also listed in Table 1. Outpatient clients had 1.4 previous alcohol or drug Table 1 Mean values of client and treatment characteristics Variable

Outpatient treatment (N/27)

Inpatient treatment (N/50)

Male (%) Female (%) Age Married (%) White (%) African
/American (%) Hispanic (%) Years of education Times in alcohol or drug treatment Treatment visits/days completed to date Visits to program, per week Travel distance to program (miles) Travel time to program (h) Travel cost to program, per visit ($) Time spent at program, per visit (h) Ever employed (%) Currently employed (%) Hours worked per weeka Hourly rate of pay ($)a Treatment interferes with work (%)a Hours missed from work to attend treatment, per visita

62.96 37.04 37.41 (8.67) 18.52 14.81 44.44 37.04 11.83 (2.42) 1.41 (1.34)

48.00 52.00 36.60 (6.13) 22.00 18.37 54.00 26.00 11.86 (2.31) 2.56 (3.06)

50.89 (107.3)

86.82 (85.27)

1.89 (0.75) 15.09 (14.50)

n/a n/a

0.71 (0.38) 7.62 (10.27)

n/a n/a

1.88 (0.85)

n/a

100.0 63.00 41.17 (10.82) 12.72 (10.20) 29.60

94.00 16.00 41.33 (24.02) 12.59 (24.02) n/a

0.38 (0.91)

n/a

S.D.s in parentheses for continuous variables; n/a, not applicable or not available. a Conditional on being currently employed.

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treatment episodes, while the inpatient clients incurred 2.6. Number of treatment visits/days completed in the present programs amounted to 51 visits for outpatient clients and 87 days for inpatient clients. The average client in outpatient treatment made about 1.9 visits to the program per week, traveled a one-way distance of 15 miles, incurred $7.62 per visit in travel expenditures, and spent about 1.9 h at the program per visit. Every outpatient client reported an employment history, but only 63% were currently employed. For the inpatient clients, 94% reported employment during their lifetime, but only 16% were currently employed. Clients in inpatient treatment with an employment history worked an average of 41.33 h/week; clients in outpatient treatment worked 41.17 h/week. Outpatient clients reported a slightly higher hourly wage ($12.72 vs. $12.59). Finally, 30% of the outpatient clients reported that treatment interfered with their work, resulting in an average lost work time of 0.38 h per visit. The mean estimates for each of the client cost calculations (see Section 4) are reported in Table 2. Unit cost values represent the client cost per treatment visit for outpatient treatment and the client cost per treatment day for inpatient treatment. The full unit cost amounted to $49.77 per treatment visit for the average client in outpatient treatment and to $194.60 per treatment day for the average client in inpatient treatment. The full client cost per treatment visit/day is composed of time cost ($40.38 and $194.00 for outpatient and inpatient treatment), cash or in-kind payments ($1.77 and $0.06), travel cost ($7.62, outpatient only), and other costs ($0.00 and $0.23). Again, these actual dollar estimates cannot be considered representative or generalizable given the small size of the samples. Indeed, the computational procedures applied in the pilot analyses revealed substantial variance. In the future, it will be necessary to study how survey factors (e.g. question construction, time period sampled, in-

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structions to the subject and proctor) and actual variance (true cost variability across patients) contribute to the total variance and skewness of these cost distributions. To provide a statistical profile of the variance in cost estimates, unit cost estimates were calculated for the 25th, 50th, 75th, and 100th percentiles. These quartile estimates demonstrate that the data are highly skewed to the right. For example, the mean unit cost estimates for outpatient and inpatient treatment ($49.77 and $194.6) were considerably higher than the median unit cost estimates ($40 and $128). The magnitude of the incurred costs depended on total time spent in treatment up to the day of the administration of the instrument. For the present Pilot Study, the administration of the surveys was scheduled for convenience rather than on the same date or time in treatment for all clients. At the times the surveys were conducted, all participating clients still had additional treatment visits/days left to complete. For most purposes, it may be preferable to administer the Client DATCAP at the end of the program so that a cost estimate can be obtained for an entire treatment episode. Nevertheless, the incurred cost estimates reported here provide at least a partial profile of client costs incurred during an active treatment episode. The total incurred cost amounted to $3251 for the average client in outpatient treatment and $16 372 for the average client in inpatient treatment. Total incurred cost is composed of time cost ($2514 and $16 358 for outpatient and inpatient treatment), cash or in-kind payments ($85.85 and $2.29), travel cost ($650.4, outpatient only), and other costs ($0.00 and $12.04). Again, quartile estimates demonstrated a rightward skew in the data. The median total incurred cost was considerably lower than the mean for both outpatient ($610 vs. $3251) and inpatient ($9160 vs. $16 372) treatment. These results indicate that time cost accounted for the largest share of the cost estimates, implying that the

Table 2 Mean values of client cost estimates (2000 dollars) Variable

Cash or in-kind payments Travel cost Time cost Other costs Total cost 25th percentile 50th percentile 75th percentile 100th percentile

Outpatient treatment (N/27)

Inpatient treatment (N/50) a

Cost per visit

Cost of total treatment received

Cost per day

Cost of total treatment receiveda

1.77 (6.03) 7.62 (10.27) 40.38 (28.61) 0.00 (0.00) 49.77 (33.70) 27.5 40 69.38 147.5

85.85 (313.6) 650.4 (2434) 2514 (5377) 0.00 (0.00) 3251 (7366) 152 610 1768 32 760

0.06 (0.40) n/a 194.3 (373.4) 0.23 (0.94) 194.6 (373.4) 95 128 168 2672

2.29 (16.16) n/a 16 358 (37 443) 12.04 (54.61) 16 372 (37 441) 3869 9160 17 982 267 200

S.D.s in parentheses; n/a, not applicable or not available. a Note that cost of total treatment received refers to the costs incurred by the patient from the day of treatment entry to the day the Client DATCAP was administered.

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biggest client sacrifice made to attend treatment was the opportunity cost of labor and leisure time forgone. Time cost for inpatient treatment largely exceeded that of outpatient treatment, which obviously can be explained by the full-time commitment associated with inpatient treatment, preventing employment or leisure activities. Travel cost represented the second largest cost category for outpatient treatment. Cash or in-kind payments and other cost for both modalities were rather small.

6. Amendments to the Client DATCAP Based on observational, survey-specific, and statistical findings, as well as suggestions from colleagues and anonymous reviewers, several amendments and enhancements were made to the original modules of the Client DATCAP. First, a survey design expert was hired to improve the structural layout and visual appeal of the instrument. Although most changes to the format are rather subtle, the improved format is expected to enhance comprehension and accuracy. Second, for Edition 2 of the Client DATCAP, it was decided to ask the respondent’s name, patient number or ID, and the last four digits of their social security number, rather than preserving respondent anonymity, as was the case for the Pilot Study. Patient identifiers will enable analysts to obtain crucial information from program records, rather than relying on patient recall for measures such as treatment length-of-stay. Asking for patient identifiers led to further changes in the instrument as some of the demographics can now be directly obtained from program records. Accordingly, all questions in both modules of the Client DATCAP pertaining to demographics or measuring the number of treatment visits/days received and expected are now considered redundant and have consequently been removed from the instrument. Third, Question S11 in both modules, which asks respondents whether they were attending treatment together with a partner or family member(s), was deleted. Although this information is important for calculating the full ‘‘familial’’ cost of treatment, it was not included in the present calculations because the focus here was on the direct client costs of treatment. Future studies may decide to add this question if they intent to estimate the costs incurred by a partner or other family members. Fourth, as briefly mentioned in Section 5.2, questions related to cash or in-kind payments and other (miscellaneous) costs did not instruct the respondent to write down zero when no costs were incurred, resulting in many blank answers. Rather than automatically treating a blank as zero cost, these questions were reconstructed to include two parts. The first part asks whether the respondent incurred any costs. A respondent with an

affirmative answer is subsequently requested to stipulate the type of cost and corresponding amount in part two. This new design enables distinction between answers of zero cost and blank or refused answers. Fifth, travel costs are now collected for clients in both outpatient and inpatient treatment. Although clients in inpatient modalities obviously travel less frequently than outpatient clients, travel costs might be quite substantial as inpatient clients sometimes choose to enter treatment away from their direct surroundings for reasons of privacy or to obtain better treatment. Thus, a question was added to Edition 2 of the Client DATCAP-I asking the client to specify costs incurred to travel to the program. Sixth, some outpatient clients were unable to estimate the total miles they traveled to attend treatment (Question S14 , outpatient module). Note that this question was merely meant to enable analysts to calculate travel costs in case the respondent failed to report travel expenditures, but was not actually used for the present analysis. Nevertheless, a backup question was included in Edition 2 of the instrument that asks the respondent to specify the origin (i.e. zip code) of their travel so that driving distance traveled could be calculated electronically using GEOCODING software. Seventh, questions S17 (inpatient module) and S25 (outpatient module), which ask the respondent to stipulate their rate of pay before taxes, were rewritten to specify all types of legal compensation (including tips) to ensure that all income from employment is measured. Eighth, in Edition 2 of the Client DATCAP, the question measuring cash or in-kind payments now gives instructions on which items should be considered as inkind payments. More specifically, it instructs the participant to include volunteering time, time spent preparing food, and donated supplies or equipment, but not to include any contributions that are part of therapy or treatment plan, such as leading group meetings. Finally, it was decided to measure more accurately the leisure time for clients in inpatient treatment. For the Pilot Study, it was assumed that daily leisure time amounted to 24 h minus the hours of work reported and 8 h of sleeping time. In reality, however, leisure time may vary beyond these parameters as free time may differ substantially across programs and may hinge on personal habits, such as number of hours of sleep per day. Thus, we revised the Client DATCAP-I to include a question asking the respondent to specifically report any free time during a typical day in treatment, including time spent sleeping and eating. Thus, daily leisure time for Edition 2 of the instrument will be calculated as the difference between 24 h and the hours of work plus the amount of free time reported. An important limitation of this question is that the respondent might not distinguish between true leisure time and controlled

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leisure time assigned as part of the therapy. Nonetheless, it is expected that under this method the estimate of individual’s leisure time will be more accurate than previous calculations.

7. Discussion and conclusion The principle aims of the Client DATCAP Pilot Study were to (1) test the feasibility and client acceptability of the Client DATCAP instrument; (2) examine and understand the range and magnitude of client-specific costs of substance abuse treatment; and (3) determine the practicality of proctored self-administration. First, the preliminary findings suggest that the self-administered Client DATCAP is a feasible and acceptable instrument for estimating costs incurred by clients in treatment, with completion time amounting to less than 10 min. Second, client costs appeared to be higher than expected and to have a considerable range across respondents, with time costs consistently accounting for the largest cost component. Third, self-administration under the research protocol and design was practical. On the basis of this initial qualitative information and numerous suggestions from colleagues and reviewers, the format and content of the instrument (public release Edition 2) were revised substantially. It is believed that these changes will reduce variability and improve validity of the estimates beyond the levels shown in the Pilot Edition. Unit cost estimates for outpatient (visit) and inpatient (day) treatments seem plausible, but incurred costs were considerably higher than expected. The average client cost per treatment visit for outpatient treatment amounted to $49.77, and the average client cost per treatment day for inpatient treatment amounted to $194.60. Unit cost estimates were subsequently used to calculate costs incurred from the start of treatment until the day the instrument was administered. The resulting total incurred cost amounted to $3251 for the average outpatient client and $16 372 for the average inpatient client. For both modalities, time cost by far accounted for the largest component of total cost, followed by travel cost (outpatient only). It is important to emphasize here that unit costs are the most relevant estimates for treatment research and policy analysis as these values are independent of time spent in treatment, which is always program and/or client specific. Unit cost estimates represent normalizing factors, especially in the context of the present Pilot Study since average completed treatment time for both modalities was relatively high (51 visits for the average outpatient client and 87 days for the average inpatient client). As more applications of the Client DATCAP are completed, unit cost results could be used for perfor-

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mance monitoring, policy analysis, and economic evaluations. To provide some perspective on the magnitude of the client cost estimates, a comparison was made with the program cost estimates for an average treatment episode. Considering resource use and cost data from all outpatient programs that completed the DATCAP, the program-specific cost for an average outpatient episode amounted to $1974 in 2000 dollars (French et al., 1997; French and McGeary, 1997; Salome´ and French, 2001; unpublished data), compared with $3251 in clientspecific incurred cost for the average outpatient client in this Pilot Study. Similarly, the program-specific cost for the average inpatient episode (short-term and longterm combined) amounted to $8414 in 2000 dollars, compared with $16 372 in client-specific incurred cost for the average study participant. These comparisons demonstrate that, even in a partial treatment episode, client costs appear to be an important component of the total cost of addiction treatment5. Despite the encouraging results obtained regarding the feasibility of estimating client costs of treatment, some important limitations of the design and execution of this Pilot Study should be discussed. One essential shortcoming of the present study was the absence of a sensitivity analysis of the cost estimates. Again, due to the small sample size and limited scope of the Pilot Study, testing the validity of the estimates was not a top priority. Nevertheless, it is strongly suggested that future analyses test alternative assumptions, especially with regards to estimating the time cost of treatment. In particular, it is suggested that a sensitivity analysis be conducted at two levels. First, it was assumed for the Pilot Study that anyone reporting an employment history had full-time employment potential at a wage rate equal to the rate reported. Although it is justifiable that the opportunity cost of time should equal the best possible alternative use of the respondent’s time (i.e. equivalent to the highest possible wage rate), it is also reasonable to assume that this scenario might not apply to each individual. Therefore, employment potential at the reported wage rate could be realistically considered only for those participants reporting employment in the past year, as opposed to anytime in their lives. When applying this assumption to the present analysis for outpatient clients, the unit and incurred time cost estimates decreased from $40.38 to $34.93 and from $2514 to $2447. For inpatient clients, the unit and

5 It is of course important to caution the reader that any direct comparisons of program against client costs should preferably take place within the same program and for an identical treatment episode, while taking precautions to avoid double counting of the client and program costs.

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incurred time cost estimates decreased from $194.3 to $184.8 and from $16 358 to $15 579. Second, a sensitivity analysis could use different rates altogether, ranging from the minimum wage rate to the full hourly wage rate reported for valuing employment time, and from 0 to 150% of the full hourly wage rate reported for valuing leisure time. When applying the minimum wage rate for employment time, unit and incurred time cost estimates declined from $40.38 to $16.90 and from $2514 to $998.6 for the average outpatient client, and from $194.3 to $82.40 and from $16 358 to $7154 for the average inpatient client. Valuing leisure time at a different rate had no effect on the present estimates for the outpatient sample because each respondent reported an employment history. When valuing leisure time at zero for the inpatient sample, unit and total time cost estimates declined from $194.3 to $96.73 and from $16 358 to $8806; when valuing leisure time at 150% of the reported wage rate (or minimum wage rate in case of no employment history), unit and incurred cost estimates increased to $234 and $20 232. A second limitation of the present calculations pertains to the assumption that the client costs incurred remained constant over time. In reality, costs might have varied over the course of treatment delivery, as is sometimes the case for cash payments. Unfortunately, it appears almost impossible to adequately capture changes in costs through the Client DATCAP. Therefore, when dealing with a modality or program with different phases of treatment, it is suggested that future applications administer the Client DATCAP either during each treatment phase or during a typical treatment phase. A third limitation relates to the possibility of double counting costs of addiction treatment, as currently some overlap exists between the Client DATCAP and the Program DATCAP. Most importantly, client cash or inkind payments contribute to program revenue and support the delivery of treatment services, and therefore may be simultaneously reported at the program level. Thus, whenever joining cost estimates from both the Client and the Program DATCAPs, precautions should be taken to avoid entering the same cost twice. In this respect, it is important always to distinguish the specific type of cash or in-kind payments and other costs. A final shortcoming relates to calculating travel costs. Given the great variability in travel expenses, no specific instructions are provided to the respondent on how to calculate costs incurred for traveling back and forth to the program when traveling by car (i.e. whether to consider items such as insurance, gasoline, and depreciation). Since reporting of such costs by the respondent could turn out to be very arbitrary, it is suggested that a standard mileage rate should instead be applied. In other words, total travel costs could be calculated

manually by the interviewer based on this standard mileage rate as well as the number of miles traveled to the program. This manually calculated estimate should take precedence over the travel costs reported by the client. In conclusion, the Client DATCAP was tested, at least in a preliminary way, through a small Pilot Study at both outpatient and inpatient treatment programs. The process, survey-specific, and quantitative results of the Pilot Study led to the redesign of the instrument and the launch of Edition 2 of the outpatient and inpatient modules (French, 2002a,b) (see http://www.DATCAP.com or request a copy from the corresponding author). Future applications will provide further evidence as to the utility and acceptability of the instrument. In this regard, it is important to emphasize that the instrument was designed to be flexible and suitable for use at diverse treatment programs and across geographical areas. Furthermore, supplemental questions could always be added to the instrument to represent unique program or geographical characteristics. In fact, applications of the instrument across modalities, programs, organizations, and geographical boundaries, including those outside the US, are not only feasible but encouraged as repeated use will expose the instrument’s strengths and shortcomings and provide further opportunities for enhancements. Program administrators, policy makers, and addiction researchers have long recognized the presence and importance of client costs in the delivery of addiction services. In most economic evaluations of addiction treatment, however, these costs are not addressed. By introducing a supplemental module to the Program DATCAP to measure costs incurred by clients, the present study may represent an important contribution to the addiction literature.

Acknowledgements Financial assistance for this study was provided by the National Institute on Drug Abuse (grant numbers 1R01 DA11506 and 2P50 DA07705) and the National Institute on Alcohol Abuse and Alcoholism (grant number 1 R01 AA13167-01). We are grateful to Silvana Zavala for research assistance throughout the study, Carri Brewer for her design work on the instruments, Jody Sindelar for helpful suggestions on earlier Editions of the Client DATCAP, three anonymous reviewers for excellent feedback on the original manuscript, and Carmen Martinez, William Russell, and Michelle Peart for their administrative and editorial assistance. This research was completed while Dr French was an Associate Professor at the Department of Epidemiology and Public Health and the Department of Economics, University of Miami, Miami, Florida. The authors are

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entirely responsible for the research conducted in this paper, and their position or opinions do not necessarily represent those of the National Institute on Drug Abuse, the National Institute on Alcohol Abuse and Alcoholism, the University of Miami, the Medical University of South Carolina, The Village treatment organization, or the Treatment Research Institute.

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