title: Capture recapture estimation of the prevalence of mild intellectual disability and substance use disorder.
abstract: Persons with mild to borderline intellectual disability (MID) have been identified as a group at risk for substance use disorder (SUD). However, prevalence estimates of co-occurring SUD and MID rely largely on single source studies performed in selected samples. To obtain more reliable population estimates of SUD and MID, this study combines data from an Intellectual Disability Facility (IDF), and an Addiction Treatment Centre (ATC) in a semi-rural area in the Netherlands. Capture-recapture analysis was used to estimate the hidden population (i.e., the population not identified in the original samples). Further analyses were performed for age and gender stratified data. Staff members reported on 88 patients with SUD and MID in the IDF (4.0% of the IDF sample) and 114 in the ATC (5.2% of the ATC sample), with 12 patients in both groups. Only strata for males over 30 years provided reliable population estimates. Based on 97 patients in these strata, the hidden population was estimated at 215. Hence the estimated total population of males over 30 years old with MID and SUD was 312 (95% CI 143-481), approximately 0.16% (0.05-0.25%) of the total population of this age and gender group. This illustrates that while patients with co-occurring SUD and MID often receive professional help from only one service provider, single source data underestimate its prevalence, and thus underestimate treatment and service needs. Therefore, population prevalence estimations of co-occurring SUD and MID should be based on combined multiple source data.
authors: Tactus Addiction Treatment, Raiffeisenstraat 75, 7514 AM Enschede, The Netherlands; Nijmegen Institute for Scientist-Practitioners in Addiction, Radboud University Nijmegen, P.O. Box 6909, 6503 GK Nijmegen, The Netherlands; Aveleijn, Grotestraat 260, 7622 GW Borne, The Netherlands. Electronic address: j.vandernagel@tactus.nl.
authors: Joanneke E L
authors: JE
authors: VanDerNagel
authors: Nijmegen Institute for Scientist-Practitioners in Addiction, Radboud University Nijmegen, P.O. Box 6909, 6503 GK Nijmegen, The Netherlands; Aveleijn, Grotestraat 260, 7622 GW Borne, The Netherlands. Electronic address: m.kiewik@aveleijn.nl.
authors: Marion
authors: M
authors: Kiewik
authors: Tactus Addiction Treatment, Raiffeisenstraat 75, 7514 AM Enschede, The Netherlands; Department of Psychology, Health & Technology, University of Twente, P.O. Box 217, 7500 AE Enschede, The Netherlands. Electronic address: m.postel@tactus.nl.
authors: Marloes G
authors: MG
authors: Postel
authors: Tactus Addiction Treatment, Raiffeisenstraat 75, 7514 AM Enschede, The Netherlands; Nijmegen Institute for Scientist-Practitioners in Addiction, Radboud University Nijmegen, P.O. Box 6909, 6503 GK Nijmegen, The Netherlands. Electronic address: marike.vandijk@tactus.nl.
authors: Marike
authors: M
authors: van Dijk
authors: Trajectum, P.O. Box 300, 7200 AH Zutphen, The Netherlands; Behavioural Science Institute, Radboud University Nijmegen, P.O. Box 9104, 6500 HE Nijmegen, The Netherlands. Electronic address: r.didden@pwo.ru.nl.
authors: Robert
authors: R
authors: Didden
authors: Department of Cognitive Neuroscience, Nijmegen Centre for Evidence-based Medicine, Radboud University Medical Centre, P.O. Box 9101, 6500 HB Nijmegen, The Netherlands. Electronic address: j.buitelaar@donders.nl.
authors: Jan K
authors: JK
authors: Buitelaar
authors: Nijmegen Institute for Scientist-Practitioners in Addiction, Radboud University Nijmegen, P.O. Box 6909, 6503 GK Nijmegen, The Netherlands. Electronic address: nispa.dejong@gmail.com.
authors: Cor A J
authors: CA
authors: de Jong
mesh_terms: D000328:Adult; D003625:Data Collection; D005260:Female; D006801:Humans; D008607:Intellectual Disability / Q000453:epidemiology*; D008297:Male; D008875:Middle Aged; D015233:Models, Statistical; D009426:Netherlands; D015995:Prevalence; D012720:Severity of Illness Index; D019966:Substance-Related Disorders / Q000453:epidemiology*; D055815:Young Adult
keywords: Capture recapture method; Intellectual disability; Prevalence estimation; Substance use disorder