Table I.
Characteristics of cohort studies of diabetes and brain tumor incidence and mortality.
| First author (Refs.) | Source and starting-ending year | Study design | No. of participants | Diabetes assessment | Outcome ascertainment | Cases | Type of DM | FU (years) | Confounding factors |
|---|---|---|---|---|---|---|---|---|---|
| Adami HO (14) | Sweden 1965–1983 | Cohort | 51,008 (M/F) | Medical records | Cancer registry | 66 | No assessment | Mean 5.2 | 1,5 |
| Wideroff L (15) | Denmark 1977–1989 | Cohort | 109,581 (M/F) | Discharge diagnosis | Cancer registry | 159 | No assessment | Mean 5.7 | 1,2,5,11 |
| Zendehdel K (16) | Sweden 1965–1999 | Cohort | 29,187 (M/F) | Discharge diagnosis | Cancer registry | 32 | Type 1 | Mean 14.4 | 1,2,5,11 |
| Coughlin SS (17) | USA 1982–1998 | Cohort | 1,056,243 (M/F) | Self-report | Mortality registry | 87 | No assessment | Mean 14.7 | 1,4,7,8,9,10, 13,14,15,16 |
| Jee SH (18) | Korea 1992–2002 | Cohort | 829,770 (M) | Self-report or blood glucose level | Cancer registry and records | NA | No assessment | Mean 10 | 1,3,8,9 |
| Swerdlow AJ (19) | UK 1972–1993 | Cohort | 28,900 (M/F) | Discharge diagnosis | Cancer registry | 16 | Type 1 and 2 | Mean 18 | 1,2,5,17 |
| Chodick G (20) | Israel 2000–2010 | Cohort | 100,595 (M/F) | Self-report or blood glucose level | Cancer registry | 12 | No assessment | Mean 8 | 1,6,7,19,26 |
| Hemminki K (21) | Sweden 1964–2007 | Cohort | 125,126 (M/F) | Medical records | Cancer registry | 304 | Type 2 | Median 15 | 1,2,6,18,20,29 |
| Shu X (22) | Sweden 1964–2006 | Cohort | 24,052 (M/F) | Discharge diagnosis | Cancer registry | 20 | Type 1 | Mean 18.3 | 2,6,27,28 |
| Atchison EA (23) | USA 1969–1996 | Cohort | 594,815 (M) | Discharge diagnosis | Cancer registry | 527 | No assessment | Mean 10.5 | 1,2,4,18,23 |
| Lam EK (24) | Asia Pacific region NA | Cohort | 367,361 (M/F) | Self report, diagnosis or blood glucose level | NA | 168 | No assessment | Median 4 | 1 |
| Carstensen B (25) | Denmark 1995–2009 | Cohort | The Danish population (M/F) | Medical records | Cancer registry | 418 | No assessment | NA | 1,2,5,12,21,22 |
| Lo SF (26) | Taiwan 1996–2009 | Cohort | 1,790,868 (M/F) | Medical records | Cancer registry | 397 | Type 2 | Median 3.5 | 1,2,23,24,25 |
NA, not available; DM, diabetes mellitus; FU, follow up; M, male; F, female; Confounding factors: 1, age; 2, gender; 3, age2; 4, ethnicity; 5, calender year; 6, region; 7, body mass index; 8, smoking; 9, alcohol consumption; 10, red meat consumption; 11, excluding the first-year of follow-up; 12, excluding the first month-year of follow-up; 13, education; 14, consumption of citrus fruits and juices; 15, consumption of vegetables; 16, physical activity; 17, country-specific person-years at risk; 18, obesity; 19, cardiovascular diseases; 20, socioeconomic status; 21, duration of diabetes/insulin treatment; 22, date of birth; 23, chronic obstructive pulmonary disorder; 23, urbanization; 24, hypertension; 25, hyperlipidemia; 26, Supplemental Educational Services (SES) level; 27, age at first hospitalization; 28, period of diagnosis; 29, time period.