before and after the initiation of the Avahan programme, the difference between the preintervention and postintervention average yearly rates of increase was calculated for each district, and the statistical significance of the difference between the rates assessed ( table 3 ). Retrospective analysis of condom use trends: summary: comparison of pre- and postintervention rates of CCU increase (slopes) using linear regression with GEE, by district Differences in yearly rates of pre- and postintervention increase varied from ?9.2% to +21.7%. This means, for example, that in the case of condom use by brothel-based sex workers with regular clients in Pune (Maharashtra), the average yearly increase in rates was about 9% greater before the start of Avahan than after it (negative inflection point). Conversely, in the case of condom use by sex workers with occasional clients in Guntur (Andhra Pradesh), the average yearly increase in rates was about 22% greater after the start of Avahan than before it (positive inflection point). In a number of districts, the pre -- post difference in rates was not significant, indicating that the yearly rate of increase in condom use was not different after than before initiation of Avahan (no inflection point). To summarise these results: in the case of both regular and occasional clients, 10/21 districts had a positive inflection point, 9/21 had no inflection point, and 2/21 had a negative inflection point. In districts with significantly different post- and preintervention slopes (n=12), the number of districts with a positive inflection point (n=10) was significantly