States are also expected to develop estimates of treatment need on a statewide and local basis and report them to CSAT in their block grant applications and through STNAP. Under the 1992 Alcohol, Drug Abuse, and Mental Health Administration Reorganization Act (P.L. Through STNAP, CSAT provides states with funding and technical assistance to conduct studies to determine the need and demand for substance abuse treatment in relation to the states’ resource availability. NHSDA Limitations Affect the Accuracy of National Estimates of Drug Abuse Treatment Need

Although OAS relies primarily on NHSDA to make national estimates of drug abuse treatment need for the general population and certain subpopulations, the survey has limitations that can lead to underestimates of treatment need. OAS’ Adjusted NHSDA Data Provide a Higher Estimate of Treatment Need by Compensating for Some Undercounting

To partially account for NHSDA’s undercoverage of hard-to-reach populations and underreporting of drug use by survey respondents, OAS developed a methodology that substitutes data from sources presumed to be more reliable. Using this methodology, OAS estimated that in 1995, about 8.9 million people in the United States needed drug abuse treatment compared with the 6.9 million estimate—including 2.6 million women—derived solely from NHSDA. While this adjustment results in a treatment need estimate that is about 29 percent higher than the estimate based on only NHSDA data, it still results in conservative estimates of treatment need. A regression model OAS developed in 1996 uses NHSDA sample data and local area indicators to estimate state-level drug prevalence and treatment need. SAMHSA expects the expanded NHSDA to improve its prevalence estimates of drug abuse in the 50 states and the District of Columbia—one of the goals included in its 1999 performance plan. However, SAMHSA officials and other experts believe that more validation is needed overall in the methods used to estimate drug abuse treatment need. Our review of needs assessment information in states’ fiscal year 1997 block grant applications found the data to be incomplete and of questionable quality. According to SAMHSA, this is due, in part, to states’ lack of sufficient data and resources to complete the extensive amount of data required in block grant applications. Although one of SAMHSA’s performance goals is to increase to 80 percent the proportion of state applications that include STNAP needs assessment data, SAMHSA did not provide any information in the performance plan on how it will increase state reporting or verify the data reported by states in block grant applications. While SAMHSA has efforts under way to improve its national estimates through the expansion of NHSDA, the survey is still likely to result in an underestimate of treatment need. Even though states are required to provide estimates of treatment need as part of their block grant applications, not all states report this information and some of the data reported are inaccurate. (See tables 1 and 2.)
Why GAO Did This Study

Pursuant to a congressional request, GAO reviewed the need for drug abuse treatment, focusing on: (1) the Substance Abuse and Mental Health Services Administration's (SAMHSA) efforts to estimate drug abuse treatment need on a national basis, including estimates of subpopulations, and possible limitations of these efforts; and (2) state estimates of drug abuse treatment need.

What GAO Found

GAO noted that: (1) SAMHSA's national estimates of drug abuse treatment need are primarily derived from the agency's National Household Survey on Drug Abuse (NHSDA); (2) while NHSDA is the principal measure of the prevalence of illicit drug use in the United States, SAMHSA and others have recognized that certain survey limitations affect the accuracy of need estimates, which may result in an underestimate of treatment need; (3) NHSDA's reliance on self-reported data likely results in underreported drug use; (4) to compensate for these limitations, in 1996, SAMHSA developed a method for assessing treatment need that adjusts NHSDA prevalence data with other data sources, including crime reports and treatment facility data; (5) SAMHSA estimated that in 1995, about 8.9 million people in the United States needed treatment for an illicit drug, compared to its estimate of 6.9 million derived solely from NHSDA data; (6) beginning in 1999, SAMHSA will expand NHSDA to provide better national drug use estimates of subpopulations and to provide state estimates of prevalence and treatment need; (7) in any case, these adjustments will only partially correct NHSDA's limitations and are likely to still result in an underestimate of treatment need; (8) states use various methods to develop estimates of treatment need, which are used to help make planning and resource allocation decisions; (9) states are required to report these estimates in applications for federal block grant funds for substance abuse prevention and treatment; (10) GAO's review of fiscal year (FY) 1997 block grant applications show that not all states submitted such data, and of those that did, some submitted incomplete or inaccurate data; (11) according to SAMHSA, the incomplete and inaccurate data are due, in part, to states' lack of sufficient data and resources to complete block grant applications; (12) in response to prior concerns about the lack of state and substate estimates of treatment need, the State Treatment Needs Assessment Program (STNAP), administered by the Center for Substance Abuse Treatment (CSAT), was initiated in 1992; (13) under 3-year contracts with CSAT, states are provided financial and technical assistance for conducting needs assessments and developing estimates of treatment need to include in their block grant applications; and (14) SAMHSA has established the improvement of state STNAP needs assessment reporting as a goal in its FY 1999 performance plan.