For interpreting TDI data, variations in coverage of treatment entries between countries and over time need to be taken into consideration. We attempted to consider differences in coverage of TDI data, i.e., the share of all relevant treatment units covered by the indicator, between country and over time. However, a complete assessment of TDI coverage is not available but the most recent report for the year 2014 marks substantial cross-country differences in the TDI coverage rates – from 60% to 100% for out-patient treatment centers and from 30% to 100% for in-patient treatment centers (for country-specific and temporal data, see Supplemental Material 1 - Supplementary Figure 1 and Supplementary Material 2) [38]. To further elaborate on TDI coverage variations, we examined how the number of treatment units covered by the TDI differs between countries and developed over time (all data taken from EMCDDA website: [35]).
