Table 1. Characteristics of prospective studies included in the systematic review.
Reference | Study country | Study design | BV outcome measure | HC-type used | BV diagnostic method | Sample size | % BV positive | % using HC | HC-use comparison group | Unadjusted OR/RR (95% CI) | Reporteda Adjusted OR/RR (95% CI) |
Amsel 1983 [75] | USA | CS | prevalence | COC | Amsel | 311 | 22.2 | 26.0 | non-combined/NC | 0.91 (0.46–1.74) | |
Lefevre 1988 [77] | France | CS | prevalence | COC | Amsel | 370 | 26.0 | 38.9 | non-HC/NC | 0.72 (0.43–1.21) | |
Barbone 1990 [45] | USA | RCT/LC | incidence | COC | modified Amsel | 818 | 38.8 | 75.4 | non-combined/TL | 0.84 (0.63–1.10)b | |
Moi 1990 [78] | Sweden | CS | prevalence | COC | Amsel | 3762 | 26.0 | 53.0 | non-combined/NC | 0.73 (0.63–0.85) | |
Hillier 1991 [79] | USA | CS | prevalence | COC | Amsel | 630 | 32.4 | 35.1 | non-combined/NC | 0.62 (0.42–0.90) | |
Hart 1993 [58] | Australia | CS | prevalence | COC | modified Amsel | 4341 | 16.9 | 41.3 | non-combined/NC | 0.85 (0.72–1.00) | |
Cohen 1995 [38] | Thailand | CS | prevalence | COC | Amsel | 144 | 34.0 | 61.8 | non-combined/NC | 0.44 (0.21–0.96) | 0.50 (0.20–1.20) |
POC | Amsel | 144 | 34.0 | 14.6 | non-POC/NC | 1.15 (0.34–3.93) | |||||
Shoubnikova 1997 [12] | Sweden | CS | prevalence | COC | Amsel | 956 | 13.7 | 69.0 | non-combined/NC | 0.51 (0.35–0.77) | 0.40 (0.20–0.80) |
Guerreiro 1998 [80] | Portugal | CS | prevalence | u-HC | modified Amsel | 781 | 7.55 | 52.0 | non-HC | 0.20 (0.13–0.49) | |
Zenilman 1999 [46] | USA | CS | prevalence | COC | Amsel | 272 | 30.5 | 20.6 | non-combined/NC | 0.63 (0.29–1.29) | |
Calzolari 2000 [14] | Italy | CS | prevalence | COC | Amsel | 1314 | 16.3 | 12.6 | non-combined/NC | 0.47 (0.25–0.82) | 0.43 (0.22–0.76) |
Baeten 2001 [18] | Kenya | LC | incidence | COC | Nugent | 948 | 39.0 | 15.5c | NC/TL | 0.80 (0.70–1.00) | |
POC | Nugent | 948 | 39.0 | 17.8c | NC/TL | 0.70 (0.50–1.00) | |||||
Fonck 2001 [40] | Kenya | RCT/CS | prevalence | COC | Nugent | 431 | 49.0 | 27.8 | non-combined/NC | 1.36 (0.88–2.11) | |
Holzman 2001 [59] | USA | CS | prevalence | u–HC | Nugent | 496 | 30.0 | 37.3 | non-HC/NC | 0.47 (0.28–0.81) | 0.50 (0.20–0.80) |
Joesoef 2001 [57] | Indonesia | prevalence | u-HC | Nugent | 357 | 32.5 | 47.3 | non-HC/NC | 0.60 (0.37–0.96) | ||
Dan 2003 [81] | Israel | CS | prevalence | COC | Nugent | 176 | 24.0 | 14.8 | non-combined/NC | 0.62 (0.24–1.47) | |
Ness 2003 [29] | USA | CS | prevalence | u-HC | Nugent | 1135 | 64.0 | 44.1 | non-HC/NC | 0.52 (0.40–0.67) | 0.60 (0.40–0.80) |
Yen 2003 [13] | USA | CS | prevalence | u-HC | Nugent | 1938 | 27.0 | 36.8 | non-HC/NC | 0.75 (0.60–0.94) | 0.78 (0.62–0.98) |
Grio 2004 [82] | Italy | CS | prevalence | COC | Amsel | 5230 | 7.95 | 17.7 | non-combined/NC | 0.75 (0.56–1.01) | |
Schwebke 2004 [44] | USA | RCT/CS | prevalence | u-HC | Nugent | 250 | 44.8 | 36.4 | non-HC/NC | 0.71 (0.41–1.24) | |
Smart 2004 [83] | Australia | CS | prevalence | u-HC | Spiegel | 1780 | 5.7 | 30.6 | non–HC/NC | 0.67 (0.54–0.83) | 0.60 (0.51–0.81) |
Watcharotone 2004 [24] | Thailand | CS | prevalence | u-HC | Amsel | 800 | 14.6 | 41.9 | NC/TL | 0.97 (0.50–1.90)b | |
Ashraf-Ganjoei 2005 [25] | Iran | CS | prevalence | COC | Amsel | 130 | 37.7 | N/Ad | non-HC/NC | 0.37 (0.14–0.99)b | |
Bradshaw 2005 [15] | Australia | CS | prevalence | COC | Amsel/Nugent | 342 | 46.0 | 46.8 | non-HC/NC | 0.62 (0.39–0.97) | 0.60 (0.40–1.00) |
Harville 2005 [48] | USA | CS | prevalence | u–HC | Nugent | 411 | 26.3 | 42.1 | non–HC/NC | 0.61(0.37–0.98) | |
Plitt 2005 [43] | USA | RCT/CS | prevalence | COC | Nugent | 115 | 60.0 | 20.9 | non-combined/NC | 1.05 (0.38–3.04) | |
Schwebke 2005 [47] | USA | LC | incidence | u-HC | Nugent | 96 | 69.8a | 41.7e | non-HC/NC | 0.49 (0.17–1.40)b | |
Bradshaw 2006 [10] | Australia | LC | recurrence | u-HC | Nugent | 122 | 55.7a | 38.7 e | non-HC/NC | 0.40 (0.20–0.80)b | 0.50 (0.30–1.00) |
Amaral 2007 [35] | Brazil | CS | prevalence | u-HC | Nugent | 155 | 75.5 | 44.5 | non-HC/NC | 0.56 (0.25–1.26) | |
Cauci 2007 [84] | Italy | CS | prevalence | COC | Nugent | 500 | 29.0 | 27.2 | non-combined/NC | 0.49 (0.29–0.80) | |
Evans 2007 [85] | UK | CS | prevalence | u-HC | Ison-Hay | 169 | 14.4 | 50.3 | non-HC/NC | 0.77 (0.29–2.00) | |
Hassan 2007 [36] | Africa | RCT/CS | prevalence | POC | Nugent | 237 | 33.8 | 24.5 | non-POC/NC | 0.76 (0.38–1.51) | |
Kleinschmidt 2007 [51] | South Africa | CS | prevalence | POC | Nugent | 551 | 34.7 | 54.4 | non-HC/NC | 0.96 (0.67–1.38) | |
Koumans 2007 [30] | USA | CS | prevalence | COC | Nugent | 3739 | 29.2 | 10.4 | non-combined/NC | 0.65 (0.40–1.00) | |
Riggs 2007 [16] | USA | CS | prevalence | COC | Nugent | 8542f | 40.0f | 29.4 f | non-combined/NC | 0.64 (0.55–0.74)b | 0.76 (0.63–0.9) |
POC | Nugent | 8542f | 40.0f | 25.8 f | non-POC/NC | 0.76 (0.66–0.88)b | 0.64 (0.53–0.76) | ||||
LC | incidence | COC | Nugent | 2636 | 31.2 f | non-combined/NC | 0.92 (0.73–1.17)b | 1.13 (0.88–1.43) | |||
POC | Nugent | 2636 | 24.4 f | non-POC/NC | 1.04 (0.78–1.39)b | 1.07 (0.79–1.45) | |||||
LC | recurrence | COC | Nugent | 2892 | 84.2 | 21.5 f | non-combined/NC | 0.68 (0.53–0.87)b | 0.76 (0.56–1.03) | ||
POC | Nugent | 2892 | 84.2 | 19.0 f | non-POC/NC | 0.61 (0.48–0.79)b | 0.6 (0.44–0.81) | ||||
Cherpes 2008 [52] | USA | LC | incidence | COC | Nugent | 773 | 36/100g | 62.9g | NC | 0.80 (0.60–1.10)b | |
POC | Nugent | 773 | 36/100g | 280.7g | NC | 1.20 (0.80–1.90)b | |||||
Mares 2008 [86] | Brazil | CS | prevalence | COC | Nugent | 40 | 57.5 | 12.5 | non–combined/NC | 0.48 (0.04–4.79) | |
POC | Nugent | 40 | 57.5 | 22.5 | non–POC/NC | 0.90 (0.16–5.51) | |||||
McClelland 2008 [37] | Kenya | RCT/LC | incidence | POC | Nugent | 151 | 37.1 | 28.5 | NC/TL | 0.59 (0.48–0.73)b | 0.60 (0.48–0.74) |
Peipert 2008 [60] | USA | RCT/CS | prevalence | u-HC | Amsel/Nugent | 523 | 31.0 | 69.0 | non-HC/NC | 0.75 (0.48–1.16) | |
Rugpao 2008 [53] | Thailand | LC | incidence | COC | Amsel | 1522 | 10b | 35.9 | non-combined/NC | 1.00 (0.75–1.33)b | |
incidence | POC | Amsel | 1522 | 10b | 42.1 | non-POC/NC | 0.77 (0.57–1.02)b | ||||
Baisley 2009 [42] | Tanzania | CS | prevalence | u-HC | Nugent | 1305 | 62.9 | 46.2 | non-HC/NC | 0.72 (0.56–0.93) | 0.80 (0.62–1.04) |
Fethers 2009 [55] | Australia | CS | prevalence | COC | Nugent | 528 | 4.7 | 40.2 | non-combined/NC | 0.82 (0.32–1.99) | |
Pettifor 2009 [49] | South Africa | LC | incidence | POC | Nugent | 567 | 35.6 | 19.9 | non-POC/NC | 0.75 (0.55–1.02)b | 0.77 (0.56–1.06) |
Rifkin 2009 [27] | USA | CS | prevalence | COC | Amsel | 330 | 40.3 | 58.2 | NC/TL | 1.01 (0.67–1.52)b | 0.66 (0.39–1.10) |
POC | Amsel | 330 | 40.3 | 17.0 | NC/TL | 0.42 (0.24–0.74)b | 0.42 (0.20–0.88) | ||||
Tibaldi 2009 [26] | Italy | CS | prevalence | COC | Amsel | 24122 | 8.9 | 16.5 | non-combined/NC | 0.86 (0.72–1.04)b | 0.69 (0.56–0.85) |
Yotebieng 2009 [39] | Thailand | RCT/CS | prevalence | u-HC | Amsel | 901 | 57.0 | 24.9 | non-HC/NC | 0.46 (0.34–0.64) | |
Brotman 2011 [56] | USA | CS | prevalence | u-HC | Amsel | 93 | 67.0 | 12.9 | non-HC/NC | 1.00 (0.24–4.95) | |
Bukuski 2011 [50] | Kenya | RCT/LC | recurrence | u-HC | Nugent | 164 | 42.7 | 33.5 | non-HC/NC | 1.11 (0.77–1.60) | |
Kampan 2011 [87] | Malaysia | CS | prevalence | u-HC | Amsel | 131 | 19.1 | 49.6 | non-HC/NC | 0.86 (0.32–2.23) | |
Gallo 2012 [54] | USA | LC | incidence | COC | Amsel | 645 | 39.5 | 29%h | non-combined/NC | 0.67 (0.45–0.91)b | 0.59 (0.42–0.91) |
Mascarenhas 2012 [88] | Brazil | CS | prevalence | u-HC | Nugent | 100 | 20.0 | 41.0 | non-HC/NC | 0.95 (0.30–2.86) | |
Perla 2012 [41] | Peru | CS | prevalence | COC | Nugent | 212 | 44.8 | 10.8 | non-combined/NC | 0.62 (0.23–1.66) | |
Bradshaw 2013a [17] | Australia | RCT/LC | recurrence | COC | Nugent | 404 | 28.0 | 27.2 | non-combined/NC | 0.63 (0.41–0.96) | 0.52 (0.34–0.81) |
Bradshaw 2013b [7] | Australia | CS | prevalence | COC | Nugent | 1093 | 11.8 | 53.5 | non-combined/NC | 0.60 (0.40–0.80)j | 0.60 (0.40–0.90) |
LC | incidence | COC | Nugent | 864 | 11.8 | 53.5i | non-combined/NC | 0.70 (0.50–1.00)b | 0.70 (0.50–1.10) |
all adjusted OR/RRs are as reported by authors,
OR/RRs calculated by authors, raw data not available,
baseline prevalence used,
raw data on the % using OC not available, on the basis of the odds ratios reported, the proportion of women using contraceptives were calculated to well exceed 10%,
per number of visits,
number or percentage of assessments rather than number of participants reported, gwoman-years, calculated by authors,
raw data was not available, but parent study from which this cohort was derived reported 29% using HC [89],
baseline prevalence of women using combined methods of contraception was 53.5% of which most went into the longitudinal analysis, but raw data was not reported,
unadjusted ORs clustered by clinic so included as reported. Key: HC = hormonal contraception, COC = combined oestrogen- and progesterone-containing methods of HC, POC = progesterone only containing methods of HC, u-HC = unspecified HC, CS = cross-sectional study, LC = longitudinal cohort, RCT = randomised controlled trial (either LC used or CS data used), OR = odds ratio, RR = risk ratio, NC = no contraception used, TL = tubal ligation.