Mikael Dahlberg

The hidden population : Some methodological issues about estimation of problematic drug use

Aim This article analyses and discusses the estimation of serious or problematic drug use through an empirical example based on a local Swedish study in Gothenburg. Methods and Data This was a case-finding study with questionnaires directed at organisations which have contact with the target group. The material was supplemented with information from the two documentation systems DOK and ASI. A total of 2,148 reports were collected. Health care data of 1,096 individuals was also collected for analysis with the truncated Poisson method. Analyses with capture-recapture or truncated Poisson were conducted to calculate the size of the hidden population. Results The statistical analyses resulted in variable numbers for the hidden population, and the total prevalence of serious drug abuse in Gothenburg is estimated to be between 2,200 and 4,400 people. Conclusion The study shows that estimation of the presence and prevalence of problematic drug abuse involves many methodological difficulties and challenges. The significant variation of the size of the hidden population presented in the study raises doubts about the reliability and validity of the different methods. The methods are clearly sensitive to the importance of fulfilling the different basic assumptions.

Psychometric properties of the UngDOK : A structured interview for adolescents with substance-use problems

Aim: This article describes and discusses the Swedish UngDOK interview and its psychometric properties. Method: The study is based on empirical data from 1633 intake interviews collected by 15 units in ten cities and focused primarily on the two central sections of intake form: alcohol and drug use and mental health. The statistical analyses concern internal consistency, test–retest reliability, discriminant validity and internal non-response. Results: The reliability of AUDIT-C and the mental health domain was good with regard to both internal consistency and test–retest. The test–retest values were generally satisfactory, except for frequency of drug use and association with peers who use drugs. The discriminant validity shows that the interview clearly distinguishes adolescents with more profound problems from a group with milder problems and that a minor degree of inconsistency and non-response bias may occur in empirical material based upon self-reported information. Conclusion: The study showed that the psychometric properties of the UngDOK interview are generally satisfactory and may be regarded as a valuable option for practices engaged in treating adolescents with substance-use problems.

Inter-rater reliability – a reliable measure for standardised : A case study on the DOK interview

Aims Inter-rater reliability studies are unusual as regards the standardised interview instruments used in the Swedish treatment care system for substance abusers. This article presents the results of a study intended to establish the inter-rater reliability of DOK interviews, through identification of question areas and items with high or low correspondence, and through analysis of how ratings differ between different interviewers. Methods & Data In total 41 practitioners participated in this study, with various experiences and from six different treatment units of the Swedish treatment care system for substance abusers. Participants gave their ratings and completed the DOK questionnaire based on a video-taped interview. Calculation and analysis of the correspondences were carried out for each individual question area and also each individual item by using appropriate statistical methods. Differences between the various assessors are presented. Results The results of the study show that the percentage agreement for the question areas and the items is generally high, with the exception of a few isolated questions. Conclusions Among the many possible different explanations for a lack of correspondence is that the questions could be ambiguously constructed and defined or the interview guidelines do not offer satisfactory guidance, or some questions could be too detailed. In addition, a few of the raters may lack sufficient training or experience when it comes to conducting interviews based on DOK. The combined results of the study show that there is a high level of inter-rater reliability, which indicates that in practice it is possible to utilise structured interviews such as DOK.Inter-rater reliability studies are unusual as regards the standardised interview instruments used in the Swedish treatment care system for substance abusers. This article presents the results of a ...

Gender differences among adolescents with substance abuse problems at Maria clinics in Sweden

Aim: The article describes similarities and differences regarding various risk factors between girls and boys with substance abuse problems who begin outpatient treatment at the Maria clinics in Sweden. Potential hypotheses and some implications are also discussed. Methods: This cross-sectional study was based on interview data from 2169 adolescents obtained over three years from outpatient clinics in 11 Swedish cities. Results: Girls appear to consistently have more difficult family and childhood environments than boys, and are more likely to have problems related to school, more serious substance abuse problems, and more severe mental health problems. Criminal activity is significantly higher among boys. Conclusions: The study shows that girls entering treatment generally have significantly more risk factors than boys and thus more extensive problems in several aspects of life, which in turn increases the risk of developing serious drug and alcohol problems in adulthood. The study supports the gender-paradoxical relationship in which a smaller proportion of girls than boys enter treatment for substance abuse, even though girls tend to have more problematic life situations.