Discussion and Implications

Broad Patterns of Stability and Gradual Change

The NDATUS survey monitors the scope of specialty treatment activities, particularly treatment services funded by Federal and State governments. From its inception as a public surveillance and accounting tool in the mid-1970's, the survey has taken a series of one-day census "snapshots" that broadly describe providers and clients in specialty substance abuse treatment, and the treatment services delivered. This series of snapshots invites longitudinal comparisons.

Seven NDATUS surveys reported that the number of providers grew by about 50% and total clients in specialty treatment nearly doubled between 1980 and 1992. However, interpretation of this growth is problematic because, prior to 1992, the survey did not estimate the number of non-responding providers nor the number of clients treated by non-responding providers. Furthermore, the total number of providers, their size, and total NDATUS clients may reflect changing State reporting practices that were not well documented. Thus, the reported growth in providers and NDATUS clients over time may reflect survey artifacts as well as real phenomena.

Artifacts due to variable response rates are least confounding when comparing selected ratios over time. These ratios have the number of clients or providers with an interesting characteristic in the numerator and all clients or all providers respectively in the denominator. In this way, variation in absolute numbers due to different response rate cancel out. As discussed above, the proportion of clients by demographic groups, by institutional setting, and by type of treatment service appeared to be relatively stable between 1980 and 1992 or they changed only gradually.

This apparent stability has two implications. First, it suggests that at least these NDATUS data have a high "signal to noise" ratio over time. If noise were problematic, the data would have bounced noticeably up and down, from survey to survey. Second, it suggests that reported growth in the number of specialty treatment clients over these 12 years was not accompanied by major structural changes in the treatment system.

One gradual change -- the aging of clients in treatment -- corroborates similar findings from the National Household Survey on Drug Abuse (NHSDA) and the Drug Abuse Warning Network (DAWN). The NHSDA found that the proportion of drug users 35 and older increased from 10% of drug users in 1979 to 28% of users in 1993 [SAMHSA 1994b]. Similarly, the proportion of DAWN emergency room visits related to cocaine, for patients 35 and older, grew from 12% in 1979 to 34% in 1992 [SAMHSA 1993c]. Although evidence of aging in NDATUS pertains to all substance abuse clients, the aging process found in all three surveys may be explained by the aging of an unusually large group of young people who started using addictive substances in the 1960s and 1970s [Gfroerer and Brodsky 1992].

Gradual changes in these NDATUS clients and services ratios, between 1980 and 1992, may also help to allay concerns about NDATUS reporting discontinuities that might have resulted from major Federal policy shifts -- first away from and then back toward emphasis on services data collection. The stability of NDATUS data reported over this turbulent period suggests that the States and treatment providers maintained basic reporting practices.

National Framework for a Family of Services Studies

As an annual national census of specialty providers NDATUS updates the National Facility Register (NFR); and the NFR frames the universe for nationally representative sample surveys. Because they contact fewer respondents, sample surveys can collect more detailed and more systematic data about specialty treatment services, clients, and outcomes.

Using the precursor to NFR (SAFIS) to frame the universe, NIDA funded national surveys of outpatient providers in 1988 and 1990 [see Appendix 4 and Price et al]. Also in 1990, NIDA sponsored the Drug Services Research Study [SAMHSA 1992] of all specialty treatment for drug abuse [SAMHSA 1992]. SAMHSA is currently sponsoring three more sample surveys: the Services Research Outcome Study (SROS), the National Treatment Study (NTS), and the Alcohol and Drug Services Survey (ADSS). NDATUS is also used to identify and monitor providers that the States believe should report admissions records to the Client Data System (CDS).

NDATUS and CDS data take alternative views of the specialty treatment system. On the one hand, the NDATUS one-day census estimates the daily caseload (or stock) of clients by treatment type. In conjunction with other treatment data concerning resources used per client for each treatment type, these caseload estimates can be used to estimate the resources required to operate the specialty treatment system.

On the other hand, CDS admissions records detail client characteristics for each treatment episode. Admissions over time represent the flow of clients into the specialty treatment system. This flow, coupled with discharges, maintains the NDATUS daily caseload of clients. Furthermore, CDS admissions can be summed to provide data for an entire year, rather than just one day. A year is a better period to measure the number and demographic mix of clients who have been able to receive treatment more or less when they need it. It also more accurately reflects the relative contribution of shorter term (and often more intense) 24-hour treatment programs which accumulate treatment episodes more rapidly over time than longer term, outpatient programs. Finally, a year is also particularly relevant for policy analysis because it corresponds to a budget cycle.

In addition to spawning other national studies, NDATUS together with these other data sources outlines the national context for States to assess their own specialty treatment systems. Indeed, comparisons of State data in this report reveal wide variation in key variables such as the number of clients in treatment per 100,000 population, and the proportion of clients in 24-hour detoxification versus 24-hour rehabilitation versus outpatient rehabilitation. Some variation may be due to reporting practices, but large differences indicate opportunities for further study. They may also suggest certain States as models for improving specialty services in the rest of the nation.

A National Baseline to Evaluate Future Change

Specialty substance abuse treatment is part of larger health care and social services systems that are under fiscal pressure to make structural changes. It is also part of the criminal justice system that will receive new funds and responsibilities under the 1994 Federal Anti-Crime Act. To permit before and after comparisons, a goal for future analysis is to use the family of national and State services studies to develop a mid-1990s baseline for specialty substance abuse treatment services.

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