1. GENERAL POPULATION SURVEY METHODOLOGY
Janusz Sieroslawski
Institute of Psychiatry and Neurology
Warsaw
GENERAL POPULATION SURVEY METHODOLOGY
General population survey (GPS) on prevalence and consumption of drugs, opinion, knowledge about drugs and risk
Belgrad, 25th of February – 1st of March 2013

2. Population surveys in Poland
Quite long tradition of the countrywide general population surveys focused on alcohol consumption (1962, 1968, 1976, 1984, 1989, 1993, 1995, 1998, 2002, 2006, 2010)
Questions on drug use in 1984 and 1989 included – only a few cases of illicit drug use found
In 1997 first general population survey on drug use covering Warsaw only
Since 2002 country wide population surveys each 4 years (2006, 2010)

3. Aims and objectives of the studies
Monitoring of drug use and alcohol consumption and exploring of attitudes toward drug and alcohol problem as a aim of the study
Objectives of the study related to the drugs
to assess prevalence of occasional drug use in general population
to identify factors of occasional drug use
to explore attitudes toward drug addiction and various approaches to drug policy

4. Study design
Studies commissioned by National Bureau for Drug Prevention
Field work conducted by contracted agency
Target population – Poland’s inhabitants age 15-64
Respondents selection: random sample
Data collection technique – face-to-face interview (pen and paper)
Data processing using SPSS PC

5. Questionnaire -1 Questionaire developed on the basis of EMQ
Questions with predefined answers
Drugs, alcohol, tobacco, prescribed drugs under study
Particular drugs use explored in life-time, last 12 months and last 30 days time frame (number of times, age of onset)

6. Questionnaire -2
Indicators of drugs availability (perceived availability, exposer to drug offers)
Alcohol consumption measurement in 12 months time frame
Beverage Specific Quantity Frequency method
Screening instruments (AUDIT)
Nominations for „benchmark” estimation
Opinions on drug problem and different approaches to the problem

7. Population Territorial (geographical) coverage Age coverage
Countrywide
Overrepresentations of some regions
Age coverage
15-64
Overrepresentations of 15-34
Inhabitants of Poland regardless nationality
Stay as a criterion instead of registration
People living in institutions (prison, shelter, military barracks) excluded

8. Sampling
Sampling method – multistage stratified random sample with overrepresentations of some subpopulations
First stage – small geographical areas
Second stage – households
Third stage - respondents
Sampling frame – electronic data base of haushold addresses
Sampling output – houshold addresses
Weighting procedure to reduce bias (gender, age and education level)

9. Weighting Weighting procedure to reduce bias related to:
overrepresentations
nonresponses
gender
age groups
rural – urban areas
Weighting lead to sample size reduction

10. Data collection – field work procedure
Pilot study – to test questionnaire and fieldwork procedures
Special training procedure for interviewers:
practical exercise interviewing
instruction for interviewers in the written form
probation interview to test interviewers’ skills
Field control of the interviewers’ job
The letter explaining study and announcing interviewers’ visit sent before field work phase
Interview duration: minutes

11. Interviewer bias Substance use very sensitive issue
Interviewer could influence respondents answers by manifesting own attitudes
Interviewer have to establish confidence and provide a sense of security
Selection of interviewers
Interviewers training focus on:
how to establish confidence and provide a sense of security
how to avoid manifestation of own attitudes

12. Ethical issues
Anonymity of respondents as the crucial factor of the data reliability
Data protection mechanisms applied:
interviewers obliged to keep secret of information collected and to protect data
respondents’ names always separated from the fulfilled questionnaires
face-to-face interview always without presence of other persons
data base without names
Agreement of respondent for giving interview requested