Age, period, and cohort effects on trends in outpatient addiction care utilization in the general Berlin population from 2008 to 2016.

BACKGROUND: The aim of this study was to decompose independent effects of age, period, and cohort on trends in outpatient addiction care utilization resulting from alcohol (AUD) and illicit substances use disorders (ISUD). Decomposing trends in addiction care utilization into their independent effects by age, period, and cohort may lead to a better understanding of utilization patterns. METHODS: Individuals seeking help in Berlin outpatient addiction care facilities between 2008 and 2016 with an age range of 18-81 years for AUD (n = 46,706) and 18-70 years for ISUD (n = 51,113) were standardized to the general Berlin population using data from the German Federal Statistical Office. Classification of utilization as AUD- (F10) or ISUD-related (F11, F12, F14, F15, F16, F18, F19) help-seeking was based on primary diagnoses according to the International Statistical Classification of Diseases and Related Health Problems. Age was measured in years and period as year of data collection. Cohort was defined as the mathematical difference between period and age. Age, period, and cohort analyses were conducted using the intrinsic estimator model on AUD- and ISUD-related outpatient addiction care utilization. RESULTS: Age effects on AUD-related utilization were highest in 18- to 19-year-old and in 39- to 59-year-old individuals. ISUD-related utilization declined almost continuously with increasing age. Period effects on AUD- and ISUD-related utilization were small. AUD-related utilization was highest in cohorts born from 1951 to 1986. ISUD-related utilization increased in cohorts born between 1954 and 1973 where utilization peaked, followed by a decline of the same order. CONCLUSIONS: Age and cohort effects were the strongest drivers of trends in AUD- and ISUD-related outpatient addiction care utilization. Onset of help-seeking in earlier phases of AUD development should be enhanced as well as help-seeking for AUD and ISUD in general. The highest cohort-related rates in the baby boomer and following cohorts for AUD and ISUD underline an increased demand for addiction care.

Substance use disorder and the baby boom generation: Does Berlin outpatient addiction care face a sustained change?

INTRODUCTION: The ageing of baby boomers is expected to confront addiction care with new challenges. This cohort had greater exposure to psychoactive substances in youth than earlier cohorts. In this study, we aimed to investigate whether Berlin addiction care is confronted with a sustained change in its clientele initiated by the baby boomers. METHODS: Using data from Berlin outpatient addiction care facilities, we contrasted type of primary substance use disorder and number of comorbid substance use disorders in baby boomers with an earlier and a later cohort. To isolate cohort effects, two-level random intercept regression models were applied in the overlapping age groups of the baby boomer cohort with each of the other cohorts. RESULTS: Compared with the earlier cohort, alcohol use disorder lost importance whereas illicit substance use disorder gained importance in the baby boomers. Baby boomers presented a higher number of comorbid substance use disorders than the earlier cohort. Comparing baby boomers with the later cohort, these relationships pointed in the opposite direction. DISCUSSION AND CONCLUSIONS: Outpatient addiction care faces a sustained change to more illicit and comorbid substance use disorders. With increasing life expectancy and the ageing of baby boomers marked by higher substance use than previous cohorts, older clients, who had been under-represented in outpatient addiction care, will gain relevance. Hence, addiction care has to adapt its offers to appropriately meet the changing needs of its clientele.