“How many adults use methamphetamine?” and “How many adults with methamphetamine use disorder receive treatment?” require different denominators. A 2020 report by Jones, Compton and Mustaquim demonstrates why the distinction matters. It analyzed U.S. survey data from 2015–2018, so its figures are historical estimates rather than current prevalence.
Who was actually surveyed?
The analysis used 171,766 adults participating in the National Surveys on Drug Use and Health. The underlying surveys sampled noninstitutionalized U.S. civilians and used a probability design and weights to generate population estimates. The adult analysis included people aged eighteen and older.
The estimated 1,626,200 adults reporting past-year methamphetamine use was an annual average for the pooled period. It was not the unweighted number of respondents who reported use, and it was not a sum of four nonoverlapping annual populations. Someone represented in one annual estimate could also use methamphetamine in another year.
What did 6.6 per 1,000 mean?
The estimated annual average rate of past-year use was 6.6 per 1,000 adults, with a 95% confidence interval of 6.1–7.1. The denominator was the represented adult population, not only people using drugs, treatment entrants or people stopped while driving.
The estimate came from self-reported use. The study did not administer methamphetamine or establish exposure with quantitative blood testing. It therefore cannot identify a dose, purity, concentration, last-use time or impairment level for the people represented.
Why is 52.9% a different figure?
Among adults reporting past-year methamphetamine use, 52.9% met the survey’s criteria for past-year methamphetamine use disorder. The denominator had now narrowed to people reporting use. This percentage does not mean 52.9% of all U.S. adults had that disorder.
The disorder classification was based on self-reported answers corresponding to DSM-IV criteria. The authors cautioned that it was not a count of diagnoses made by health professionals. Treating every past-year exposure as a disorder would erase the distinction the study deliberately measured.
Frequency also varied: 36.2% of past-year users reported use on 1–29 days, while 27.3% reported at least 200 days. Neither “any use” nor one disorder label adequately summarizes the full distribution of reported use patterns.
What does the treatment figure describe?
Among adults meeting the survey definition of past-year methamphetamine use disorder, an estimated 31.5% received any substance-use treatment in the preceding year. That is a third denominator. “Any substance-use treatment” also does not establish the content, intensity or effectiveness of methamphetamine-specific care.
Subtracting 31.5% from 100% describes lack of reported treatment within this operational group. It cannot independently establish that every remaining person sought treatment, had an unmet clinical need of the same severity, or would respond to one particular program.
Which populations and explanations remain outside the estimate?
The surveys did not include unsheltered homeless people, active-duty military personnel or people living in institutions such as prisons. The average weighted response rate was approximately 51%. Self-report, nonresponse and population exclusions can affect estimates and generalizability.
The analysis found associations with demographic, mental-health and other substance-use characteristics. Its cross-sectional design could not establish why those associations occurred. A historical household estimate is useful population evidence when its time frame, sampling population and denominator remain attached; it cannot diagnose or characterize a specific individual.
Source
Jones CM, Compton WM, Mustaquim D. Patterns and Characteristics of Methamphetamine Use Among Adults—United States, 2015–2018. MMWR. 2020;69:317–323. doi:10.15585/mmwr.mm6912a1.
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