Unmet need for prevention: Analysis of condom use. Prepared by Justin Fenty

Transcription

1 Unmet need for prevention: Analysis of condom use Prepared by Justin Fenty

2 Research question/background Is consistent condom use associated with increased integration of HIV and SRH services? Build a general picture of how condom use relates to integrated services and whether sensitive to different categorisations of exposure to integrated services and choice of outcome measure.

3 At risk population Women in the cohort who were sexually active within the past 4 weeks AND met at least one of the following: HIV+ Never tested for HIV/result not yet known Treated, offered treatment or referred for treatment of STI since last interview More than one sexual partner since last interview

4 Outcome: consistent condom use Definition 1 Responded yes to the question Did you use a condom last time you had sex? Definition 2 Answered no to the question Since the last interview, have you had sex without using a condom?

5 Methods Descriptive analysis of condom use in Kenya FP cohort Two approaches to evaluating exposure to integrated services: (i) facility level, and (ii) individual level Calculate risk of consistent condom use and compare exposure categories using (unadjusted) relative risk. Investigate sensitivity to categorisation of integration and choice of outcome.

6 Approach 1: facility-level exposure Each facility categorised by change in index score from baseline to round 3: (i) low-low (ii) low-high (iii) high-low (iv) high-high Cross-sectional at baseline and at round 3 Additional restriction: women received services from the same facility at round 3 as at baseline Investigate sensitivity to categories based on Kenya FP index scores or all Integra facility scores.

7 Approach 1: study population (round 3) low-low low-high high-low high-high TOTALS Cohort, N = Round 3 data not available 139(38%) 198(42%) 199 (36%) 208(36%) 744 (38%) Not sexually active in past 4 weeks Sexually active but not at risk Round 3 services at the same facility At risk (63%) 19 (56%) 26 (53%) 19 (49%) N with outcome available Note: N with outcome available at baseline: 9, 16, 30, 27; Total=82

8 Change in condom use from baseline to round 3 by integration category Outcome definition 1 ( condom used at last sex ) % Round 3 Round 3 Round 3 Round 3 low-low low-high high-low high-high condom used condom not used

9 Approach 1: results n Consistent condom use Risk RR 95% CI P-value low-low low-high high-low high-high Round 3 n Consistent condom use Risk RR 95% CI P-value low-low low-high high-low high-high

10 Consistent condom use at round 3 by integration category Comparison of definitions 1 ( condom used at last sex ) and 2 ( had sex without condom since last interview ) % Definition 1 Definition 2 Definition 1 Definition 2 Definition 1 Definition 2 Definition 1 Definition 2 low-low low-high high-low high-high consistent condom use not consistent condom use

11 Approach 2: individual-level exposure Cumulative index score assigned to each individual at round 3: (i) low; (ii) medium; (iii) high Investigated category cut-points based on i) Kenya FP at risk population, and ii) all Kenya FP records. Additional restriction: women must have complete data for all rounds Outcome definitions take into account responses at every round. Total of 86 records for analysis.

12 Consistent condom use at baseline and by round 3, by cumulative integration category Outcome definition 1 ( condom used at last sex ) % Round 3 Round 3 Round 3 low medium high condom used condom not used

13 Approach 2: Results n Consistent condom use Risk RR 95% CI P-value Low Medium High Round 3 n Consistent condom use Risk RR 95% CI P-value Low Medium High

14 Consistent condom use by cumulative integration category Comparison of outcome definition 1 ( condom used at last sex ) and 2 ( sex without condom since last interview ) % Defintion 1 Definition 2 Defintion 1 Definition 2 Defintion 1 Definition 2 low medium high Consistent condom use not consistent condom use

15 Limitations Analysis based on small numbers; low power and sensitive to categorisations. Potential bias in selection of analysis populations Potential reporting bias in at risk definition (e.g. may underestimate if women do not report HIV status or number of partners) Potential reporting bias on condom use (though not expected to differ by integration score) No adjustment for confounding No account of clustering or pair-matching Approach 1 ignores integration scores in intermediate rounds

16 Summary Both approaches are consistent with lower condom use in the lowest integration category. Not yet a clear relationship between exposure to facility-level integration or individual-level integration. Both approaches sensitive to choice of categorisation not unexpected given small numbers. Review definition of analysis population. Explore differences between outcome definitions. Extend to PNC models