Abstract
Background: Because of the broad range of activities involved and high variance in clients' needs, it is challenging to measure the actual dose of case management in order to assess quality and manage outcomes.
Objective: The purpose of this research is to evaluate the impact of intervention dosage on client outcomes in different case management models within substance abuse treatment.
Method: A descriptive and repeated measures analysis from a clinical trials data set measured the dosage of case management and evaluated impact on client outcomes. A sample of 598 clients from a substance abuse treatment facility was randomized into one of four groups, assessed at intake and then followed for 1 year. Three groups received a form of case management as an intervention (n = 437), and all clients received drug treatment.
Results: Clients who engaged (actively participated) in case management were less likely to have legal and family issues but more likely to have a chronic medical condition at baseline. Dosage factors differed significantly across treatment conditions. In general, dose was significantly related to outcomes in the legal and family domains.
Conclusions: Although complex, case management intervention dosage can be measured using the model presented. Dosage determination aids cost-effective initiatives. Further research is needed to specify intervention protocols.
Quality and effectiveness initiatives seek to demonstrate that health care services produce desired outcomes. Whether a provider is administering a pharmaceutical therapeutic agent (medication) or delivering a behavioral intervention (such as case management or counseling), effective treatment entails planning and executing deliberative, structured interventions to achieve desired outcomes. For each intervention, a specified quantity, or dose, of the therapeutic agent or therapy may be prescribed; however, the actual dose delivered or received depends on multiple factors including the purity of the drug, fidelity of the treatment, and client adherence. The dose of a behavioral intervention is defined as a specified unit amount of a treatment or therapy. It is measured in terms of what is prescribed, what is perceived to have occurred by either party, or as the actual quantity that is delivered. The definition of dosage is the administration of the specified intervention in a prescribed amount (Huber, Hall, & Vaughn, 2001;Sidani, 1998).
"Criteria for the effectiveness of any intervention dose include precision, safety, and accuracy" (Huber, Hall, & Vaughn., 2001, p. 119). The importance of measuring dosage lies in the ability to provide the correct amount of an intervention to ensure that identified outcomes result. Too little or too much may not produce the desired effect on outcomes, may actually be harmful, or may waste resources. The specification of dosage refers to the amount of a therapeutic agent or action prescribed and administered or delivered. Effectiveness research seeks to determine whether what was prescribed actually was delivered (treatment fidelity) and whether desired outcomes were achieved as a result. The chance of committing a Type II error increases if the variability in the dose received is not taken into account (Sidani, 1998).
Despite the commonalities of precision, safety, and accuracy, unique distinctions exist between the dosages of medications and those of behavioral interventions. Medications involve chemical agents that are physically tangible and are measured using standardized weights and measures. Behavioral interventions rely on interpersonal interactions during service delivery that may not be measured in a standardized manner beyond identifying a general activity (e.g., an hour of counseling). Medications are approved for use only after testing for the therapeutic effects of measured amounts given in a prescribed way, including timing and route; but the evidence for behavioral interventions may be less sophisticated or less extensively tested. Behavioral interventions tend to be more person- and situation-dependent and may be selected based on the provider's expertise or other personal characteristics. Thus, great variability is likely in the actual activities that occur during a behavioral intervention.
Because the production of desired outcomes and subsequent assessment of effectiveness and value is dependent in part on knowing how to deliver the intervention, when to deliver it, and the amount of intervention to deliver, dose determination is an urgent issue for behavioral interventions. Despite discussion of the importance of dosage in nursing interventions (Brooten, 1997;Clark, 1996;Kanter, 1987, 1989;Sidani & Braden, 1998), little is known about how to measure the actual dose delivered in order to assess quality and manage outcomes. Case management can serve as a practical example for conceptualizing how to measure the dosage of behavioral interventions. "Case management is the glue of managed care...The trouble is we're not quite sure how the glue works, how much to use, or even when to use it" (Moreo, 1998, p. 67). The purpose of this article is to evaluate the impact of intervention dosage on client outcomes in different case management models within substance abuse treatment.