Table 1.
Characteristics1 of the 18 observational studies included in the pooled analysis of intrauterine device use and endometrial cancer risk
| Study | Location | Cases (n) | Controls (n) |
IUD Ascertainment |
Ever used an IUD | Availability of IUD variables |
|
|---|---|---|---|---|---|---|---|
| Cases | Controls | ||||||
| Cohort | |||||||
| Black Women's Health Study (BWHS) |
US | 132 | 528 | 1995, 1997, 1999 | 1.5% | 1.7% | current use |
| Cancer Prevention Study II Nutrition Cohort (CPS-II) |
US | 666 | 2,664 | 1992–1993 | 3.6% | 3.8% | age at first use, age at last use, duration of use, time since last use |
| Nurses’ Health Study (NHS) | 11 US states | 611 | 1,639 | 1980 | 4.3% | 5.9% | ever use |
| Swedish Women's Lifestyle and Health Study (WLHS) |
Sweden | 163 | 649 | 1991 | 51.5% | 56.1% | type, age at first use, age at last use, duration of use |
| Case-control | |||||||
| Alberta Case-Control Study on Endometrial Cancer (ALBERTA) |
Canada | 542 | 1,032 | 2002–2006 | 22.0% | 25.0% | age at first use, duration of use, time since last use |
| Australian National Endometrial Cancer Study (ANECS) |
Australia | 1,356 | 696 | 2005–2007 | 22.6% | 21.8% | type, duration of use |
| Connecticut Endometrial Cancer Study (CECS) |
Connecticut | 668 | 663 | 2004–2009 | 12.0% | 17.9% | age at first use, age at last use, duration of use, time since last use |
| California Teachers Study (CTS)2 |
California | 399 | 681 | 1995–1996 | 13.8% | 14.4% | type, age at first use, duration of use |
| Estrogen, Diet, Genetics, and Endometrial Cancer Study (EDGE) |
New Jersey | 469 | 467 | 2001–2005 | 14.3% | 19.1% | ever use |
| Fred Hutchinson Cancer Research Center Study 1 (FHCRC 1) |
Washington | 136 | 211 | 1994–1995 | 13.2% | 16.6% | type |
| Fred Hutchinson Cancer Research Center Study 2 (FHCRC 2) |
Washington | 409 | 356 | 2003–2005 | 24.9% | 24.7% | type |
| Milano Endometrial Cancer Case-Control Study 1 (MILANO 1) |
Italy | 527 | 2,394 | 1982–1991 | 0.4% | 2.8% | age at first use, age at last use, duration of use, time since last use |
| Milano Endometrial Cancer Case-Control Study 2 (MILANO 2) |
Italy | 226 | 224 | 1992–2006 | 0.0% | 3.1% | age at first use, age at last use, duration of use, time since last use |
| New York University Women's Health Study (NYU)2 |
New York | 121 | 333 | 1985–1991 | 11.6% | 15.0% | age at first use, duration of use |
| Patient Epidemiologic Data System Study (PEDS) |
New York | 536 | 531 | 1982–1998 | 5.0% | 6.2% | age at first use, duration of use |
| Shanghai Endometrial Cancer Study (SECS) |
China | 1,168 | 1,195 | 1997–2003 | 41.1% | 53.2% | type, age at first use, age at last use, duration of use, time since last use |
| Switzerland Endometrial Cancer Study (SWEC) |
Switzerland | 240 | 568 | 1988–1992 | 1.7% | 4.7% | age at first use, age at last use, duration of use, time since last use |
| US Endometrial Cancer Study (US) |
5 US clinics | 432 | 526 | 1987–1990 | 5.1% | 11.0% | type, age at first use, age at last use, duration of use, time since last use |
| Pooled studies | 8,801 | 15,357 | 13.8% | 16.8% | |||
1
Based on women included in the pooled analysis (after excluding women with missing IUD data)
2
Cohort study with IUD data collected in case-control interviews