defining alcoholism treatment episodes from mental health ... · web viewdefining alcoholism...

Defining Alcoholism Treatment Episodes from Mental Health Care Utilization Records

Kurt D. Stromberg, M. S. Melanie M. Wall, Ph.D.Sandra Pothoff, Ph.D.Robert L. Kane, M.D.

From the University of Minnesota School of Public Health, Division of Biostatistics (KS, MW),Division of Health Services Research and Policy (RK), Carlson School of Management (SP)

Corresponding author: Melanie M. Wall, Ph.D.University of Minnesota School of Public Health

Mayo Mail Code 303420 Delaware St. SE

Minneapolis, MN 55455612-625-2138

612-626-0660 (fax)[email protected]

This work was supported by a grant from the National Institute of Alcohol Abuse and Addiction (No. 1 R01 AA11781). The opinions are soley those of the authors and do not reflect official government positions.

Brief title: Defining Alcoholism Treatment EpisodesNumber of words: 3,838

COMPLETE AUTHOR INFORMATION

Corresponding author: Melanie M. Wall, Ph.D.University of Minnesota School of Public Health


Minneapolis, MN 55455612-625-2138

612-626-0660 (fax)[email protected]

Expertise: Biostatistics

Kurt D. Stromberg, M.S.University of Minnesota School of Public Health


Minneapolis, MN [email protected]: Biostatistics

Sandra Potthoff, PhDDepartment of Healthcare Management3-140 Carlson School of Management

321 19th Avenue SouthMinneapolis, MN 55455

[email protected]: Outcomes research, Healthcare management for alcoholism

Robert L. Kane, M.D.University of Minnesota School of Public Health


Minneapolis, MN [email protected]

Expertise: Outcomes research, Healthcare management for alcoholism

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Word count of Abstract: 143


Abstract

Objective: A method for defining and empirically validating episodes of alcoholism treatment

from health care utilization records is introduced.

Subjects: Utilization records from a large managed behavioral care company for a 96 month period

from 1991 to 1998 are used and include 88,188 patients having at least one alcoholism encounter

during the 8 years.

Methods: Treatment episodes are defined as a minimum number of alcoholism encounters with the

behavioral care company prior to a ``clear zone'' of no encounters. Statistical procedures to select a

subset of episode definitions from a number of candidate definitions are presented.

Methods for assessing both the convergent and criterion validity of different definitions of episodes

of alcoholism treatment are demonstrated.

Results: Based on these validation techniques a definition for alcoholism treatment episode that

requires at least 3 alcoholism encounters before a “clear zone” of 3 months is chosen.

Key Words: alcoholism, validation techniques, statistical applications,

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Introduction

An episode of care is defined in the literature as a sequence or cluster of health care services

related to a particular condition or disease [1,2]. Elements required to delimit a specific episode of

care include diagnostic information, well defined starting and stopping points, and a particular

course or dosage of treatment [1,2]. Hornbrook et. al. [1] and others have advocated the use of an

episode of care methodology in health outcomes research because “the episode defines the

boundaries of a particular health care process and a means in which to sum the total number of

health care inputs occurring during a specified illness or problem”. The episode of care

methodology can be useful in identifying clusters of services related to a particular health condition

and provides an ideal tool for comparing pre- and post-episode health outcomes. Since the episode

of care approach facilitates the aggregation of all medical inputs related to a condition or disease it

provides a mechanism to measure the effectiveness of care in treating the health problem.

In order to define an episode of care, the boundaries of the episode must first be established

[1]. The first element in identifying the boundaries of an episode of care is to determine the point

at which it begins. Criteria for establishing the beginning of an episode include the first encounter

of a patient with the health care provider related to a particular health care problem (e.g. [2]) or

point in time where medical care expenditures related to an illness first exceed levels prior to

illness (e.g.[3]). Next, the end of an episode of care must be identified. Often the end of an

episode of care can be established by a “clear zone”, or period of time where no subsequent health

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care encounters occur [2,4]. All health care encounters between the start of the episode, or index

case, and the end of the episode completely describe the episode of care.

In this study, an episode of care methodology is used to define distinct episodes of inpatient

and outpatient alcoholism treatment from health care utilization records from a large managed

behavioral care company. Previous alcoholism treatment research has either focused on narrowly

defined alcoholism treatment regimes [5] or simply used the first observed alcoholism treatment

claim (from a medical claims database) as the beginning of treatment without specification of an

end or a required minimum number of encounters for the episode (e.g. [6]). Previous non-alcohol

related studies have successfully constructed episodes of care from health care claims databases

[2,7,8]. Furthermore, the episode of care methodology has been used to evaluate resource

utilization by particular demographic groups [4], evaluate differences in health utilization resulting

from trauma [7], investigate psychiatric care utilization [4], and investigate cost effectiveness of

new treatment interventions [9].

Construction of episodes of care from health care utilization records facilitates the

investigation of health outcomes research at the population level. However, researchers have

shown that results based on comparisons made using episodes constructed from claims data can be

highly sensitive to the episode definition [3,9]. Currently, most studies employing an episode of

care methodology applied to medical claims databases lack sufficient validity checking and

sensitivity analysis. This paper presents a method for creating episodes of inpatient and outpatient

alcoholism treatment from health care utilization records and describes statistical methods for

assessing the validity of such episode definitions. The goal of this study is to define a suitable

subset of valid episode definitions based on a minimum number of inpatient and outpatient

encounters and length of clear zone. Finally, the validity of creating episodes of alcoholism

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treatment from utilization records is established using data on patient functioning collected at the

start of treatment.

Methods

Data source

Eight years of behavioral care utilization data for 88,188 patients with a DSM-IV

(American Psychiatric Association, 1994) alcohol diagnosis (291-alcoholic psychoses, 303-alcohol

dependence syndrome, 305.0-alcohol abuse) were obtained from a large national managed

behavioral care company. All utilization records with a DSM-IV alcohol diagnosis were extracted

for each of the patients from January 1, 1991 to December 31, 1998. In total, approximately 1.2

million encounters were considered. Inpatient (IP) encounters were defined as those encounters in

the utilization database of type “inpatient”, “inpatient attending physician”, “partial

hospitalization”, and “residential”. Outpatient (OP) encounters were defined as those encounters in

the utilization database of type “outpatient individual and family therapy”, “outpatient group

therapy”, and “structured program”. In the original database, IP encounters were stored both as

single records for an entire hospital stay or as individual records for each day of inpatient care. To

facilitate comparison of IP encounters, all IP records were restructured so each day of inpatient care

was stored as one individual inpatient day of care. Billing adjustments were common in the

database; to ensure that utilization records were counted only once, only one record of each

encounter type was allowed on a particular day. The data was restructured to show the number of

IP and OP encounters occurring for each patient during each of the 96 months of the study period.

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For a subset of 8,080 patients, a baseline interview to assess patient functioning had been

conducted upon entry into an alcohol treatment program as part of an outcome monitoring

program. These data were matched with the behavioral care utilization records using a unique

patient identifier. The baseline questionnaire contained patient demographic information, questions

relating to severity of alcohol and other substance abuse problems, and questions relating to

motivation of patients seeking alcohol treatment. These data were used to validate the episode

definitions as described below. Patient demographic information for both the complete dataset and

for the subset of patients who completed the baseline questionnaire is shown in Table 1.

--------------------------Table 1 here------------------------------

Treatment episode algorithm

The diversity in encounter profiles over the entire study period among patients suggests that

any method to create episodes of care from utilization records must be flexible and allow the

researcher to explore different conditions for constructing episodes of care. For example, the

outpatient encounter profile for nine randomly selected alcoholism patients with at least one

outpatient encounter is shown in Figure 1. Outpatient encounter profiles of patients in panels A,

B, C, and E have very prominent regions of high alcoholism treatment utilization, while profiles in

panels D and F have two pronounced areas of utilization that the researcher may or may not want to

combine into one episode of treatment (Fig. 1). Patients shown in panels G, H, and I appear to

have very few outpatient encounters and may not have made a serious commitment to outpatient

alcoholism treatment (Fig. 1). Thus, a suitable mechanism for constructing episodes of care should

allow the user to explore different definitions of alcoholism treatment and evaluate the performance

of each definition.

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-----------------Figure 1 here -----------------------------------

In this study, an algorithm is developed to choose the beginning and end of a treatment

episode according to three parameters inputs: 1. the minimum number of OP encounters required to

constitute an OP episode, 2. the minimum number of IP encounters required to constitute an IP

episode, and 3. the length of the clear zone (i.e. cluster of months with no encounters) for a

particular episode definition. The algorithm indicates whether each patient is treated or not

according to the specified inputs and it designates when the individual's treatment started and

ended, how many encounters it included, and whether it was an OP or IP treatment

episode. The algorithm is flexible to allow multiple treatment episodes across time within an

individual.

-----------------Table 2 here -----------------------------------

To illustrate the algorithm, Table 2 shows the outpatient alcohol encounters for three

patients for a portion of the study period between January 1995 (month 49) and April 1996 (month

64). Thus, for example, if the minimum outpatient treatment episode is defined as 3 outpatient

encounters prior to an OP-clear zone of 3 months, then patient 1 would have a single episode of OP

treatment lasting from month 50 to month 54 and containing 6 outpatient alcohol encounters. The

second patient would have a single outpatient episode lasting from month 53 to month 57

containing 56 outpatient alcohol encounters. The third patient would have two separate OP

episodes, one from month 51 to 54 containing 9 OP encounters and the second from month 61 to

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62 containing 7 OP encounters. However, if the minimum outpatient episode is defined as 3

outpatient alcohol encounters prior to an OP-clear zone of only 2 months then the first patient will

now have two outpatient treatment episodes: the first during month 50 containing 3 OP encounters

and the second from month 53 to 54 containing 3 OP encounters (because of the gap of 2 zero

months between months 50 and 53). Under this second minimum OP episode definition the second

and third patients' OP episodes remain unchanged.

Impact of episode definition on number of patients with episode

The treatment episode is defined by three different parameters that can vary. Specifically,

the minimum number of IP encounters required for an IP episode was varied from 2 to 6, the

minimum number of OP encounters required for an OP episode of treatment ranged from 2 to 6,

and the length of the clear zone (IP and OP) necessary to end an episode of treatment ranged from 1

to 6 months. A minimum of 2 encounters was used because clinicians indicated that 1 OP

encounter usually means a patient was assessed but not treated, and 1 day of IP care typically

means the patient likely received only detox. Hence, 5 5 6 = 150 different episode definitions

are considered.

We first consider how each of these parameters impacts the total percentage of patients

receiving at least one episode of alcoholism treatment (IP or OP). Clearly the more restrictive

episode definitions will tend to result in fewer patients treated, however, we want to investigate

how much influence each of the parameters has on changing the percent of patients considered

treated. An ANOVA is used to quantify the variability associated with each factor in the episode

definition. The proportion of variation explained by each parameter in the episode definition is the

value of R2 associated with each component in the ANOVA. A parameter with a large R2 implies

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that it has a substantial influence on the outcome (i.e. proportion of patients with at least one

episode of alcohol treatment).

Validation of episode definition

Several methods to validate the episode of care methodology were employed in this study

using the subset of patients who completed a baseline questionnaire. The baseline questionnaire

provided information regarding reasons patients sought alcoholism treatment, patient motivation

level, and whether patients received previous alcoholism treatment. This information provides a

mechanism to measure both convergent and criterion validity.

An episode definition with high convergent validity should be highly associated with

patient information known to be correlated with commitment to alcoholism treatment. For

example, patients wishing to achieve abstinence from alcohol generally have been shown to have

higher commitment to alcoholism treatment programs than those wishing only to control alcohol

use [10,11]. Thus, episode definitions with high convergent validity should indicate a strong

association between the probability of patients receiving either type of episode (IP or OP) and

whether patients sought to achieve abstinence from alcohol consumption. On the patient baseline

questionnaire, patients indicated whether they sought alcoholism treatment for legal reasons, health

reasons, to achieve abstinence, or control alcohol use. Odds ratios provide a measure of the

association between each of the reasons patients sought treatment and the probability a patient

received at least one episode of alcoholism treatment (IP or OP) under each of the different episode

definitions.

Patients also rated their motivation for completing a course of alcoholism treatment as poor,

fair, good, or excellent on the baseline questionnaire. Patients with high motivation for completing

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a course of alcoholism treatment upon entry into a treatment program are more likely to stay

engaged in alcoholism treatment [12]. Thus, episode definitions with high convergent validity

should also show an increase in the likelihood of having at least one episode of alcoholism

treatment (IP or OP) as patient motivation level increases. The odds ratio of having at least one

treatment episode of either type for each motivation level (using poor motivation as the reference

group) are summarized across the different definitions.

The criterion validity of each episode definition considered was established by examining

whether treatment episodes are identified when treatments are known to have occurred. During the

baseline interview, patients were asked to report if they had previous alcoholism treatment. Based

on patient responses clinicians determined whether patients had received past treatment. Clinician

decisions on whether treatment occurred or not was considered the most accurate way of

determining treatment history. Baseline interviews did not start until 1993 (month 29 of study) and

continued until 1997 (month 85), while alcoholism utilization records were available from 1991-

1998. Thus, both positive and negative predictivity [13] provide measurements of the criterion

validity of each episode definition. Specifically, positive predictivity can be measured for each

episode definition by determining the proportion of patients who report a previous episode of

treatment when the treatment episode algorithm identifies an episode of treatment prior to baseline.

Likewise, negative predictivity is measured by determining the proportion of patients not reporting

a previous episode of treatment when the treatment episode algorithm does not indicate an episode

of treatment prior to baseline. Thus, treatment episode definitions with high criterion validity

should have both high positive and high negative predictivity.

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Results

Impact of episode definition on number of patients with episode

Table 3 shows the total percentage of patients receiving at least one treatment episode of

any type (IP or OP) for a subset of 25 treatment definitions when the clear zone is held fixed at

three months. As the number of encounters required for an episode of treatment increases, the

percentage of patients receiving at least one treatment episode of any type decreases (Table 3). For

example, with a clear zone of 3 months, when only 2 IP or 2 OP encounters are required for an

episode of IP or OP treatment respectively, 68.49% of the patients would be considered treated.

However, when 6 IP or 6 OP encounters are required for an episode of IP or OP treatment

respectively, only 43.59% of the patients are considered treated. Furthermore, the decrease in the

percentage of patients with at least one alcohol treatment episode decreases faster when the number

of OP encounters increases than when the number of IP encounters increases (Table 3).

-----------------------Table 3 here ------------------

The standard deviation in the percentage of patients receiving at least one episode of either

type of treatment (IP or OP) among all the 150 episode definitions is 6.8%. An

ANOVA was used to quantify the amount of this variability explained by each of the parameters in

the definition. The proportion of variation explained by both the minimum number of OP

encounters required for an OP episode and the minimum number of IP encounters required for an

episode of IP treatment is extremely high (R2=0.995), while the clear zone accounts for less than

0.5% of the variability. This suggested that the clear zone contributes very little to the overall

variability found in the % of individuals treated so it could be fixed. In order to choose an

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appropriate length of the clear zone, a residual plot from the reduced ANOVA without clear zone

included was examined. This plot shows that there is a relationship between the residuals and clear

zone length but that it is best centered around zero when clear zone is three months (Fig. 2). Thus,

in subsequent analyses, the clear zone was held fixed at three months reducing the number of

episode definitions from 150 to 25.

-----------------------Table 4 here ------------------

-----------------------Figure 2 here ------------------

Validation of episode definition

Optimal treatment episode definitions should be strongly related to validation variables.

Thus, the next step in selecting good episode definitions was to measure both the convergent and

criterion validity for each of the 25 episode definitions considered. The 25 episode definitions

arose from fixing the clear zone length at 3 months, allowing the number of OP encounters

required for an episode of OP treatment to range from 2 to 6, and allowing the number of IP

encounters required for an episode of IP treatment to range from 2 to 6.

-------------------------Figure 3 here ---------------------

Figure 3 shows the marginal odds ratio (OR) of a patient receiving at least one episode of

alcoholism treatment (IP or OP) associated with four possible reasons patients sought alcoholism

treatment for all 25 episode definitions considered. The average ORs across the 25 episode

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definitions are 1.15 for legal reasons, 1.12 for health reasons, 1.78 for abstinence reasons, and 0.80

for control reasons. Thus, patients seeking treatment to achieve abstinence from alcohol

consumption were on average more likely (OR = 1.78) to receive at least one episode of alcoholism

treatment (IP or OP) than those patients not seeking treatment to achieve abstinence. Likewise,

patients indicating they were seeking alcoholism treatment only to control alcohol use were on

average less likely (OR = 0.80) to receive an episode of treatment across all 25 episode definitions

considered. Furthermore there was a strong association between patient motivation level and the

probability of receiving a treatment episode. Specifically, under all definitions patients with

excellent motivation had higher probability of being treated followed by good motivation,

followed by fair motivation.

None of the point estimates of the ORs for any of the four reasons patients sought

alcoholism treatment varied substantially among the 25 different episode definitions considered.

Consequently there is no clear winner based only on Figure 3 in terms of convergent validity (i.e.

clearly larger OR for all variables), but closer inspection of the general trends finds that the

definitions with 2 or 6 OP encounters are never best for any of the four variables. Consequently,

definitions with 3,4, or 5 OP encounters have slightly better convergent validity. Furthermore, the

definitions requiring only 2 or 3 IP encounters have slightly larger OR for all four variables and

thus better convergent validity.

----------------Figure 4 here --------------------

Calculation of the positive and negative predictivity of previous alcoholism treatment for

each of the 25 different episode definitions served as a method to compare the criterion validity for

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each of the 25 treatment episodes. An episode definition with high criterion validity should have

both a positive and negative predictivity close to one. The positive predictivity for the 25 episode

definitions ranges from 0.66 to 0.79 and generally increases as the restrictiveness of the episode

definitions increase (Fig. 4A). The positive predictivity increases most sharply when the minimum

number of OP encounters required for an episode of OP treatment increases from 2 to 3 and then

remains relatively constant. Negative predictivity is nearly constant across the 25 episode

definitions and only ranges from 0.729 to 0.740 (Fig. 4B).

Discussion

Episode definitions based on utilization data facilitate the comparison of health outcomes

across clinical sites and across time since definitions of treatment may vary spatially and

temporally. Previous researchers have often studied the effectiveness of alcoholism treatment

within only one treatment center (e.g. [14]) or within the context of narrowly defined alcoholism

treatment regimes (e.g. [5]). Furthermore, alcoholism treatment has changed over time from a

higher reliance on inpatient care programs to a greater tendency to place patients in outpatient

treatment programs to contain rising costs [15,16].

This research describes a methodology to test statistically a number of different definitions

of an episode of treatment for alcoholism. The results show that 1. the definition of an episode is

insensitive to the number of months required for a clear zone of no encounters, with the ANOVA

residuals centered closest to 0 when the clear zone is 3 months, 2. convergent validity, while

similar for all definitions, is slightly better for definitions with 3-5 minimum OP encounters or 2-3

minimum IP encounters, 3. criterion validity of positive predictive value increases the most when

the minimum number of OP encounters increases from 2 to 3. Based on these results, the

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definition of an episode of treatment for our subsequent research on assessing the impact of

alcoholism treatment on medical care utilization was set to a minimum of 3 IP or OP encounters

with a clear zone of 3 months.

The episode of care methodology developed in this paper allows more general inferences

regarding health outcomes to be made to larger populations of patients than may be obtained by

following specific cohorts of patients over time. Furthermore, computer based automation of

episode construction, together with the relatively inexpensive cost of obtaining utilization records

means that episodes of care can be constructed for many patients over long periods of time. The

relative ease in which episodes of care can be created with different definitions enables researchers

to begin with many candidate episode definitions and select subsets of definitions based upon the

importance of the factors composing the episode definition. The ANOVA model used in this study

provided a mechanism to quantify the relative importance of each factor in the episode definition

and subsequently greatly reduced the set of episode definitions that needed to be further examined

by fixing the clear zone length to three months. Moreover, the mechanism to evaluate both the

convergent and criterion validity of each episode definition allowed for the selection of a specific

episode definitions which can then be used for further analysis.

For alcoholism research, the episode of care provides an ideal tool for studying treatment

outcomes across clinical setting, clinical management region, or comparing pre-/post-episode

behaviors. The alcoholism treatment episode provides the exact starting time, stopping time, and

measures the intensity of alcoholism treatment regardless of the actual treatment program. For

example, this methodology could enable a better estimation of the cost offset associated with

treating alcoholism. Previous investigations of the cost offset hypothesis have often focussed on

identifying health care savings in particular cohorts of patients [16,17] where inferences may not

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have wider applicability. Other cost offset studies have focussed on large cohorts of alcoholics, but

have not adequately described the period of time in which alcoholism treatment occurred. These

studies instead focussed on comparing costs before and after a single index case of alcoholism

treatment [18,19]. Use of the episode of care methodology in cost offset analyses could establish a

better criterion in which to compare pre-treatment with post-treatment health care costs across a

diverse patient population.

We chose to study only episodes consisting of all IP encounters (IP episodes) or OP

encounters (OP episodes) and did not consider episodes composed of both IP and OP encounters.

This enabled us to detect differences in both forms of treatment. Furthermore, construction of IP

and OP episodes of alcohol treatment separately could facilitate future comparisons between the

effectiveness of IP versus OP treatment, currently a research area of some debate [16,20].

However, the methodology reported here could easily be adapted to construct mixed episodes

containing both OP and IP encounters.

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REFERENCES:

1. Hornbrook, M. C., Hurtado, A. V., and Johnson, R. E. . Health care episodes: definition, measurement, and use. Med. Care Rev. 1985; 42(2): 163-218.

2. Rosen, A. K., Houchens, R. L., Gibson, T. B., Mayer-Oakes, A. Developing episodes of care for adult asthma patients: a cautionary tale. Amer J. Med. Quality. 1998; 13(1): 25-35.

3. Mehta, S. S., Suzuki, S. S., Glick, H. A., Schulman, K. A. Determinining an episode of care using claims data. Diabetes Care. 1999;7(22) 1110-1115.

4. Kessler, L. G., Steinwachs, D. M., Hankin, J. R. Episodes of psychiatric utilization. Med. Care. 1980; 18(12): 1219-1227.

5. Trent, L. K. Evaluation of a four- versus six-week length of stay in the Navy's alcohol treatment program. J. Stud. Alcohol. 1998;59(3): 270-279.

6. Holder, H. D. and Blose, J. O. The reduction of health care costs associated with alcoholism treatment: A 14-year longitudinal study. Journal of Studies on Alcohol. 1992;53 293-302.

7. Lestina, D. C., Miller T. R., Smith, G. S. Creating injury episodes using medical claims data. Journal of Trauma: Injury, Infection, and Critical Care. 1998;45(3): 565-569.

8. Mitchell, J. B. et al. Using medicare claims for outcomes research. Medical Care. 1994;32(7): JS38-JS51.

9. Schulman, K. A., Yabroff, K. R., Kong, J., Gold, K. F., Rubenstein, L. E., Epstein, A. J., Glick, H. A claims approach to defining an episode of care. Health Services Research. 1999;34(2): 603-621.

10. Pachman, J. S., Foy, D. W., and Van Erd, M. Goal choice of alcoholics: a comparison of those who choose total abstinence vs. those who choose responsible, controlled drinking. J. Clin. Pyschol. 1978;34(3): 781-783.

11. Pendery, M. L., Maltzman, I. M., and West, L. J. Controlled drinking by alcoholics? New findings and a reevaluation of a major affirmative study. Science. 1982;217(4555): 169-175.

12. Walitzer, K. S., Dermen, K. H., and Conners, G. J. Strategies for preparing clients for treatment. A review. Behav. Modif. 1999; 23(1): 129-151.

13. Le, C. T. Applied Categorical Data Analysis. John Wiley and Sons, Inc. New York; 1998.

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14. Holder, H. D. The cost offsets of alcoholism treatment. Recent Developments in Alcoholism. 1998;14: 361-374.

15. Schuckit, M. A., 1998. Penny-wise, ton-foolish? The recent movement to abolish inpatient alcohol and drug treatment. J. Stud. Alcohol. 1998;59: 5-6.

16. Walsh, D. C. et al. A randomized trial of treatment options for alcohol-abusing workiers. NEJM. 1991;325(11) 775-782.

17. Weisner, C., Mertens, J., Parthasarathy, S., Moore, C., Hunkeler, E. M., Hu, T., and Selby, J. V. The outcome and cost of alcohol and drug treatment in an HMO: day hospital versus traditional outpatient regimes. Health Services Research. 2000;35(4): 791-812.

18. Goodman, A. C., Tilford, J. M., Hankin, J. R.,Holder, H. D., and Nishiura, E. Alcoholism treatment offseteffects: an insurance perspective. Medical Care Research and Review. 2000; 57(1) 51-75.

19. Holder, H. D. and Blose, J. O. Alcoholism treatment and total health care utilization and costs. A four-year longitudinal analysis of federal employees. JAMA. 1986;256(11) 1456-1460.

20. Parthasarathy, S., Weisner, C., Hu, T., and Moore, C. 2001. Association of outpatient alcohol and drug treatment with health care utilization and cost: revisiting the offset hypothesis. J. Stud. Alcohol. 2001;62(1): 89-97.

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Table 1: Demographic characteristics of patients in alcoholism care database.

All Subset withbaseline data

n 88,188 8,080

age(mean±sd) 40.0±11.9 40.8±9.8sex(%)F 33.2 33.3M 66.8 66.7region(%)W 15.5 6.2S 18.3 7.6MW 32.3 38.2NE 33.9 48.0alcoholism encounters>1 IP (%)1 28.9 20.2>1 OP(%)2 75.5 76.81Percentage of patients with at least 1 inpatient alcohol encounter.2Percentage of patients with at least 1 outpatient alcohol encounter.

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Table 2: Sample of outpatient alcohol encounters for three patients from study month 49 (January, 1995) to study month 64 (April, 1996).

Outpatient Alcohol Encounters per Monthmonth 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64patient 1 0 3 0 0 1 2 0 0 0 0 0 0 0 0 0 0patient 2 0 0 0 0 3 15 14 12 2 0 0 0 0 0 0 0patient 3 0 0 1 2 4 2 0 0 0 0 0 0 5 2 0 0

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Table 3: Percentage of patients receiving at least one episode of IP or OP alcoholism treatment under different definitions. Clear zone length held fixed at three months.

Minimum number of IP encounters for IP episode

Minimum number of OP encounters for OP episode

2 3 4 5 62 68.49 60.90 56.75 53.71 51.443 67.37 59.69 55.49 52.42 50.114 65.73 57.90 53.61 50.56 48.095 63.75 55.72 51.31 48.05 45.626 62.13 53.92 49.41 46.09 43.59

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Title:(S-PLUS Graphics)Creator:S-PLUSPreview:This EPS picture was not savedwith a preview included in it.Comment:This EPS picture will print to aPostScript printer, but not toother types of printers.

Figure 1: Outpatient encounter profile of nine randomly selected alcohol patients having at least one outpatient alcohol encounter.

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