Table 2.
Results of included studies reporting unintended pregnancy and pregnancy (intention undefined) in ascending order of incidence
| Study | Incidence rate (per 100 person-years) | 95% CI | Person-years of exposure | Duration (months) | Measurement of pregnancy | Frequency of measurement | Quality (%) |
| Unintended pregnancy | |||||||
| McClelland et al 77 |
7.2 | 4.5 to 10.9 | 305.4 | 12 | Urine test | Monthly | 40 |
| Watson-Jones et al 44 |
11.8 | 9.7 to 14.5 | 796 | 30 | Urine test | Quarterly on suspicion only | 53 |
| Gaffoor et al 42 |
13.4 | 6.1 to 25.4 | 67.2 | 24 | Urine test | Quarterly | 20 |
| Behets et al 40 |
20.7 | 4.3 to 60.5 | 14.5 | 1 | Urine test | Weekly | 27 |
| Braunstein et al 32 |
26.3 | 21.9 to 30.7 | 528.5 | 24 | Serum test | 6 monthly for 1 year+1 measurement in second year | 60 |
| Deschamps et al 33 |
27.3 | 23.3 to 31.7 | 615.6 | 18 | Test (unspecified) | 6 monthly | 67 |
| Chersich et al 34 |
28.0 | 22.6 to 34.3 | 335.8 | 12 | Urine test | Quarterly | 60 |
| Peterson et al 46 |
51.7 | 44.9 to 59.3 | 400 | 12 | Urine test | Monthly | 40 |
| Behets et al 39 |
53.0 | 21.0 to 110.0 | 13.2 | 2 | Urine test | Monthly | 40 |
| Lara et al 41 |
59.6 | 41.7 to 82.5 | 60.4 | 4 | Urine test | Monthly | 40 |
| Pregnancy (intention undefined) | |||||||
| Robb et al 51 |
2.0 | 1.4 to 2.9 | 1619.6 | 24 | Self-report | Quarterly on suspicion only | 21 |
| McClelland et al 37 |
2.7 | 2.1 to 3.5 | 2259.3 | 15-year open cohort * | Urine test | Monthly on suspicion only | 21 |
| Bazzi et al 54 |
3.3 | 1.4 to 5.2 | 359.6 | 24 | Self-report | 6 monthly | 43 |
| Strathdee et al 43 |
5.9 | 4.1 to 8.4 | 540.1 | 12 | Self-report | 4 monthly | 36 |
| van Loggerenberg et al 52 |
8.5 | 5.6 to 11.5 | 376.5 | 24 | Urine test | Monthly on suspicion only | 36 |
| Van Damme et al 48 |
8.6 | 6.7 to 10.8 | 837.5 | ≤24* | Urine test | Quarterly | 29 |
| Vielot et al 50 |
12.6 | 9.7 to 16.1 | 500.8 | 24 | Urine test | Quarterly on suspicion only | 50 |
| Kaul et al 47 |
13.5 | 11.3 to 16.1 | 968.0 | ≤48* | N/A | N/A | 21 |
| Priddy et al 56 |
14.2 | 7.6 to 24.3 | 91.5 | 6 | Urine test | Quarterly | 36 |
| Price et al 49 |
14.5 | 12.0 to 17.5 | 784.0 | 48 | Urine test | Quarterly | 43 |
| Liu et al 53 |
15.2 | 10.4 to 21.5 | 210.3 | 6 | Self-report | Quarterly | 71 |
| Kaewkungwal et al 36 |
15.8 | 13.0 to 19.0 | 721.0† | 42 | Urine test | N/A | 43 |
| Vandepitte et al 93 |
18.3 | 16.2 to 20.6 | 1467.0 | ≥24* | Urine test | N/A | 50 |
| Page et al 38 | 22.0 | 16.3 to 30.1 | 186.4 | 12 | Self-report | Quarterly | 50 |
| Feldblum et al 35 |
23.4 | 20.6 to 26.5 | 1067.5 | 18 | Urine test | 6 monthly on suspicion only | 43 |
*Duration varied for different participants.
†Person-time estimated by: (n_FSWs * yrs * retention) − (n_preg * yrs/2); where: n_FSWs, number of FSWs enrolled; yrs, study duration in years; retention, retention rate; n_p reg, number of women who became pregnant. We could not use the approach advocated by Vandenbrou c ke et al 95 as average follow-up time among FSWs was not known.
FSWs, female sex workers; N/A, not measured or reported, data not available from author.