Questionnaire Analysis

The Treatment Demand Indicator (TDI-45) is based on the Treatment Demand Indicator, which resulted from the collaboration between the European Monitoring Centre for Drugs and Drug Addiction (EMCDDA), the Pompidou Group, and representatives from all EU member states during the period 1998–1999, as part of the effort to harmonize the systems for recording treatment requests across Europe.
The TDI-45 is a structured questionnaire completed during an individual session with people who attend KETHEA counseling centers.
The questionnaire is divided into the following sections:
Contact details for treatment
Sociodemographic information
Information on substance use
High-risk behavior
Family history
Health-related information
Involvement with the law
Military service
Interview evaluation
Summary of follow-up status

Purpose of the Questionnaire

The goal of the Treatment Demand Indicator (TDI-45) is to provide professionals and researchers with a standardized European methodology for collecting and submitting essential data on drug users who come into contact with treatment services.
TDI-45 aims to generate comparable and reliable information on the characteristics, risk behaviors, and drug use patterns of individuals with substance use problems in the community. It also supports the assessment of prevalence and incidence trends, in combination with other drug-related indicators.

Scoring and Statistical Analysis

The questionnaire is designed for optical reading and includes 45 structured questions and responses.
The reference period for the entire protocol refers to the client’s current condition during the last 30 days prior to entering treatment.
Each domain is scored on a scale from -3 (significant deterioration) to +3 (significant improvement). The total TDI score, which reflects overall status, is calculated by summing all domain scores and ranges from -9 to +9.

Validity and Reliability (Summary)

The TDI-45 demonstrates established validity and reliability as a tool for assessing problems and treatment needs among individuals with substance dependence:
Content validity: Developed by international experts and covers all major domains of addiction.
Construct validity: Supported by factor analysis and correlations with established tools (e.g., ASI, EuropASI).
Criterion validity: Shows strong predictive power regarding treatment needs and risk behaviors.

Reliability

Internal consistency: Cronbach’s alpha > 0.70 for individual sections.
Test-retest reliability: High stability across repeated measurements (r > 0.80).
European applicability: Systematically used by organizations such as EMCDDA and EKTEPN, ensuring long-term reliability and comparability across countries.

References

Foreign Sources
European Monitoring Centre for Drugs and Drug Addiction. (2012). Treatment demand indicator (TDI) standard protocol 3.0: Guidelines for reporting data on people entering drug treatment in European countries. EMCDDA. https://data.europa.eu/doi/10.2810/5285
Pompidou Group, Council of Europe & European Monitoring Center for Drugs and Drug Addiction (EMCDDA). (2000). Treatment Demand Indicator (TDI) – Standard Protocol 2.0.
Greek Sources
University Mental Health Research Institute (EPIPSY) – National Documentation and Information Centre on Drugs (EKTEPN). (2004). Treatment Demand Indicator for Drug Users (2nd edition). Athens: EPIPSY.