Skip to main content

Table 1 Characteristics of the included studies

From: Screening for cervical cancer: a systematic review and meta-analysis

Randomized (cluster) controlled trial
Study Location Number of participants Ages (years) Screening exposure Disease definition Participant eligibility Post screening treatment Follow-up
Intervention Control
Sankaranarayanan et al. [20] India HPV: 34,126 Cytology: 32,058 31,488 30 to 59 Only 8 (<0.007%) of the eligible women had ever been screened Invasive cervical cancer; FIGO stages I+ No history of cervical cancer Cryotherapy, LEEP, conization offered for CIN; invasive cancer referred for treatment (surgery, radiotherapy) 8 years 2000 to 2007
Cohort studies
Study Location Number of participants Ages (years) Screening exposure Disease definition Participant eligibility Post screening treatment Follow-up
Herbert et al.[21] UK 116,022 (four groups based on screening history) 25 to 69 Interval since last smear: <3.5 y, 3.5 to 5.5 y, >5.5 y, no record Invasive cervical cancer; FIGO stages I+ No hysterectomy NR 3 years 1991 to 1993
Excluded: smears to investigate symptoms, referral smears in screen-detected cases
Rebolj et al. [22] Netherlands Cohort 1: 445,382 Cohort 2: 218,847 C1: 30 to 44 C2: 45 to 54 Mean interval between three consecutive negative results Invasive cervical cancer; FIGO stages NR Three consecutive negative smears in age interval; no history of CIN or cytological abnormalities NR 10 years 1994 to 2002
C1: 39 m
C2: 40 m
Case control studies
Study Location Number of participants Ages (years) Screening exposure/history Case/disease definition Control eligibility Post screening treatment Case diagnosis dates
Cases Controls
Andrae et al.[24] Sweden 1,230 6,124 20 to 99 Interval since last smear: 6 to 42 m (ages <53), 6 to 66 m (ages 54 to 65), 6 to 78 m (ages ≥66), not screened during interval Invasive cervical cancer; FIGO stages 1+ No history of cervical cancer; alive on case diagnosis date NR 1999 to 2001
Excluded: smears <6 m prior to case diagnosis
Aristizabal et al. [15] Colombia 277 554 16 to 60 Interval since last smear: 12 to 72 m prior to case diagnosis Invasive cervical cancer; excluded in situ Out-patient services from same clinic where case diagnosed or reside in same area as case NR 1977 to 1981
Excluded: smears <12 m prior to diagnosis/index date
Berrino et al.[16] Italy 121 350 NR Interval since last negative smear: 0 to 11 m, 12 to 23 m, 24 to 35 m, 36 to 47 m, 48+ m, no prior negative smear Invasive cervical cancer; FIGO stages I+ Married women hospitalized for and diagnosed with non-gynecological diseases; no history of breast cancer or hysterectomy Two controls had been treated for carcinoma in situ after a positive smear result 1978
Included: smears prior to symptoms (cases), smears prior to study mid-point (controls)
Clarke and Anderson [17] Canada 212 1,060 Mean 52 Interval since last smear: <5 y prior to case diagnosis Invasive cervical cancer; most <6 m post diagnosis No exclusion for hysterectomy NR 1973 to 1976
Included: non-symptomatic, routine examination smears
Decker et al.[25] Canada 666 3,343 ≥18 Mean 50 Interval since last smear: <5 y prior to case diagnosis Invasive cervical cancer; FIGO stages I+ No history of cervical cancer or malignant neoplasms (excluding non-melanoma skin cancer); no hysterectomy NR 1989 to 2001
Excluded: smears <6 m prior to case diagnosis
Hernández-Avila et al. [26] Mexico 397 1,005 25 to 80 Mean 48 Exposure: any lifetime smear(s), no history Invasive cervical cancer Eligibility limited only by age and area of residence NR 1990 to 1992
Excluded: smears <12 m prior to case diagnosis or control interview
Herrero et al.[18] Latin America 759 1,430 <70 Interval since last smear: 12 to 23 m, 24 to 47 m, never screened Invasive cervical cancer; FIGO stages I+ No history of psychiatric diagnoses, hysterectomy, cancer, or diseases related to exposures of interest; history of sexual intercourse NR 1986 to 1987
Excluded: smears <1 y prior to interview (mean interval between case diagnosis and: case interview 1 m; control interview 2.3 m)
Hoffman et al.[27] South Africa 524 1,540 <60 Interval since last smear: <5 y, 5 to 9 y, 10 to 14 y, ≥15 y, unknown, never Invasive cervical cancer; FIGO stages IB to IV; diagnosed ≤6 m prior to study enrollment Hospital admission not related to risk of cervical cancer NR NR late 1990s
Analysis excluding smears in prior 12 m showed no difference in findings
Jiménez-Pérez and Thomas [28] Mexico 143 311 Mean 49 Interval since last smear: 1 to 12 m, 13 to 60 m, >60 m, unknown, never Invasive cervical cancer; FIGO stages IB to IV No hysterectomy; not attending clinic for cervical screening, or any gynecologic or obstetric conditions; history of sexual intercourse NR 1991 to 1994
Excluded: smears ≤12 m prior to diagnosis/index date
Kasinpila et al.[38] Thailand 130 260 Mean 48 Interval since last smear: <6 m, 6 to 11 m, 12 to 35 m, 36+ m, never Invasive cervical cancer; diagnosed ≤3 m prior to interview No evidence of cervical disease or any other gynecological disease Cryotherapy and LEEP offered for confirmed abnormalities 2009
Excluded: smears in previous 6 m
La Vecchia et al.[19] Italy 191 191 22 to 74 Interval since last smear: <3 y, 3 to 5 y, >5 y, never Invasive cervical cancer; FIGO Stages 1+ Admitted and diagnosed with acute non-malignant, non-hormonal, non-gynecological problems <1 y prior to interview NR 1981 to 1983
Excluded: smears to investigate symptoms; cases with positive smear <1 y prior to diagnosis
Makino et al. [29] Japan 129 396 35 to 79 Interval since last negative smear to diagnosis/index date: 1 y, 2 y, 3 y, 4 y, ≥5 y Invasive cervical cancer; diagnosed <6 m after abnormal smear result No invasive cervical cancer; no hysterectomy; no previous abnormal cytology results; participated in mass screening NR 1984 to 1990
Exposure: any lifetime smear(s), no history
Excluded: smears to investigate symptoms or taken at time of diagnosis
Miller et al.[31] USA 482 934 Mean 49 Interval from last negative smear to diagnosis/index date: 1 y (0 to 18 m), 2 y (19 to 30 m), 3 y (31 to 42 m), 3 to 5 y (42 to 66 m), 5 to 10 y (67 to 126 m), >10 y (>126 m) Invasive squamous cell cervical cancer No prior hysterectomy or radiation to the pelvis NR 1983 to 1995
Nieminen et al.[23] Finland 179 1,507 30 to 91 Mean 60 Exposure: any lifetime smear(s), no history Invasive cervical cancer Eligibility limited only by catchment (reside in area served by case treatment hospital) Organized screening program provides colposcopy examinations and treatment for mild abnormalities 1987 to 1994
Excluded: smears <1 y prior to diagnosis/index date
Sasieni et al.[32] UK 348 677 ≥20 Interval since last negative smear (not immediately following a test showing abnormal results): 0 to 11 m, 12 to 23 m, 24 to 35 m, 36 to 47 m, 48 to 65 m, >66 m, no history Invasive cervical cancer; FIGO stages IB+ No hysterectomy NR 1992
Sasieni et al.[33] UK 1,305 2,532 20 to 69 Interval since last negative smear (no abnormal smear in prior 12 m): <3 y, 3<5 y, 5+ y, no history of a negative smear Invasive cervical cancer; FIGO stages IB+ No hysterectomy NR 1990 to 2001
Sasieni et al.[34] UK 4,012 7,889 20 to 69 Exposure: screening or no screening during specific age bands (for example, 20 to 21, 22 to 24, 20 to 24) related to cancers diagnosed in specific and imminent age bands (for example, 25 to 29) Invasive cervical cancer; FIGO stages I+ No hysterectomy; registered with a National Health Services general practitioner, still alive, not emigrated NR 1990 to 2008
Sasieni et al.[35] UK 3,305 6,516 20 to 69 Maximum interval between smears: <3.5 y, 3.5 to 5.5 y, >5.5 y or no smear history Invasive cervical cancer; FIGO stages I+ No hysterectomy NR 1990 to 2008
Talbott et al.[30] USA 143 143 Mean 45 Exposure: smear <3 y prior to case diagnosis or control interview Invasive cervical cancer (localized, regional or distant); excluded in situ No hysterectomy NR 1984 to 1985
Diagnostic smears: any positive result <12 m prior to diagnosis
Yang et al.[36] Australia 877 2,614 20 to 69 Exposure: 0, 1 or 2+ smears in last 4 y Invasive cervical cancer (localized and non-localized) No invasive cervical cancer diagnosis 1996 to 2003; alive at case diagnosis; no hysterectomy before end point NR 2000 to 2003
Excluded: smears <3 m prior to case diagnosis
Zappa et al.[37] Italy 208 832 <70 Interval since last smear (prior to index date): ≤3 y, 3 to 6 y, 6+ y, no record Fully invasive cervical cancer; excluded micro-invasive No hysterectomy prior to index date; alive at index date NR 1994 to 1999
Excluded: smears <12 m prior to diagnosis/index date
  1. CIN, Cervical intraepithelial neoplasia; FIGO, International Federation of Gynecology and Obstetrics; LEEP, loop electrosurgical excision procedure; NR, not reported; m, months; y, years.