Characteristics of included studies investigating the association between maternal age and type 1 diabetes, ordered by publication date
| First author, year* (reference) . | Design . | Country . | Type 1 diabetic subjects . | Control subjects . | Available confounders‡ . | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Ascertainment method (year case subjects diagnosed) . | Age at dx (years) . | n† . | Resp rate (%) . | Source (matching criteria) . | n† . | Resp rate (%) . | BO . | BW . | GA . | MD . | CS . | BF# (months) . | |||
| Dahlquist, 1992 (9) | C-C | Sweden | Swedish childhood diabetes register (78–88) | 0–14 | 2,757 | 98 | Medical birth registry (birth year, unit) | 8,271 | 100 | ||||||
| Bock, 1994 (10) | C-C | Denmark | Hosp. admission from National Patient Registry (78–89) | <16 | 837 | 98 | Birth registry (age, sex) | 837 | NA | ||||||
| Patterson, 1994 (11) | C-C | Scotland | Hosp. admission/childhood diabetes register (76–88) | 0–14 | 271 | 100 | Maternal discharge records (age, sex, area) | 1,340 | 100 | ✓ | ✓ | ✓ | ✓ | ✓ | ✓(any) |
| Wadsworth, 1997 (25) | C-C | U.K. | British Paediatric Association Surveillance Unit (92) | 0–5 | 213 | 89 | Health Authority Immunization Register | 318 | 70 | ✓ | ✓ | ✓ | ✓(4) | ||
| Gimeno, 1997 (26) | C-C | Brazil | Diabetes association/ Hospital admission (95) | 0–19 | 344 | 91 | Unclear (neighborhood, sex, age)‖ | 333 | 100 | ✓ | ✓ | ✓ | ✓(3) | ||
| McKinney, 1999 (28) | C-C | England | Yorkshire Childhood Diabetes Register (93–94) | 0–15 | 220 | 94 | General practitioner's records (age, sex) | 423 | 82 | ✓ | ✓ | ✓ | ✓ | ✓ | ✓(any) |
| Rami, 1999 (29) | C-C | Austria | Vienna type 1 diabetes register (89–94) | 0–14 | 103 | 86 | Schools (age, sex) | 373 | 80 | ✓ | ✓ | ✓ | ✓§ | ✓ | ✓(any) |
| Bache, 1999 (19)** | C-C | Denmark | Hospital admission (78–95) | 0–14 | 857 | 100 | Medical birth registry (month, sex, district) | 1,404 | 100 | ✓ | |||||
| Dahlquist, 1999 (14) | C-C | Bulgaria | W. Bulgaria type 1 diabetes register (91–94) | 0–14 | 125 | 73 | Schools and policlinics (age) | 440 | 79 | ✓ | ✓ | ✓ | ✓§ | ✓ | ✓(any) |
| C-C | Latvia | Latvian type 1 diabetes register (89–94) | 0–14 | 140 | 99 | Population register (age) | 301 | 79 | ✓ | ✓ | ✓ | ✓§ | ✓ | ✓(any) | |
| C-C | Lithuania | Lithuanian type 1 diabetes register (89–94) | 0–14 | 117 | 94 | Policlinics (age) | 266 | 73 | ✓ | ✓ | ✓ | ✓§ | ✓ | ✓(any) | |
| C-C | Luxembourg | Luxembourg type 1 diabetes register (89–95) | 0–14 | 59 | 100 | Preschools and schools (age) | 172 | 95 | ✓ | ✓ | ✓ | ✓§ | ✓ | ✓(any) | |
| C-C | Romania | Bucharest type 1 diabetes register (89–94) | 0–14 | 81 | 74 | Preschools and schools (age) | 277 | 81 | ✓ | ✓ | ✓ | ✓§ | ✓ | ✓(any) | |
| Stene, 2001 (13) | Cohort | Norway | Norwegian Childhood Diabetes Registry (89–98) | 0–14 | 1,810 | 100¶ | Norwegian medical birth registry | 1,382,602 | NA | ✓ | ✓ | ✓ | ✓ | ✓ | |
| Visalli, 2003 (30) | C-C | Italy | Lazio type 1 diabetes register (89–95) | 0–14 | 139 | 100 | Schools (age) | 703 | 91 | ✓ | ✓ | ✓ | ✓ | ✓(3) | |
| Stene, 2004 (31) | C-C | Norway | Norwegian Childhood Diabetes Registry (98–00) | 0–14 | 346 | 73 | Norwegian population registry | 1,626 | 56 | ✓ | ✓ | ✓ | ✓§ | ✓ | ✓(3) |
| Sadauskaite-Kuehne, 2004 (15) | C-C | Sweden | SE Sweden type 1 diabetes register (95–00) | 0–15 | 442 | 100 | Population register | 1,084 | 73 | ✓ | ✓ | ✓ | ✓§ | ✓(3) | |
| C-C | Lithuania | Lithuanian type 1 diabetes register (96–00) | 0–15 | 281 | 100 | Outpatient clinic‖ | 807 | 95 | ✓ | ✓ | ✓ | ✓§ | ✓(3) | ||
| Sumnik, 2004 (32) | C-C | Czech Republic | Czech Republic type 1 diabetes registry (95–00) | 0–15 | 640 | 79 | National Birth registry (age) | 32,000 | 100 | ✓ | |||||
| Marshall, 2004 (33) | C-C | England | Morecambe Bay/E. Lancashire diabetes clinics (98) | 0–15 | 196 | 83 | Health Authorities (sex, birth date) | 381 | 53 | ✓ | ✓ | ✓ | ✓§ | ✓(any) | |
| Cardwell, 2005 (34) | Cohort | N. Ireland | N. Ireland type 1 diabetes register (71–01) | 0–14 | 990 | 92¶ | Northern Ireland Child Health register | 439,647 | NA | ✓ | ✓ | ✓ | ✓ | ✓ | ✓(any) |
| Sipetić, 2005 (35) | C-C | Serbia | Belgrade Hospital admission (94–97) | 0–16 | 105 | 91 | Hospital outpatients with skin disease‖ (age, sex, area) | 210 | 100 | ✓ | ✓ | ✓ | ✓§ | ✓ | ✓(4) |
| Svensson, 2005 (36) | C-C | Denmark | Danish register of childhood diabetes (96–99) | 0–14 | 602 | 100 | Danish population register (age, sex) | 1,459 | 100 | ✓ | ✓ | ✓ | ✓ | ✓ | ✓(4) |
| Bottini, 2005 (20)** | C-C | Sardinia | Hospital diagnosis | ? | 189 | ? | Consecutive births in northern Sardinia | 5,460 | ? | ||||||
| Polańka, 2006 (37) | C-C | Poland | Upper Silesia Diabetes Register (89–96) | 0–14 | 394 | 87 | Central Bureau for Statistics | 994,460 | 100 | ✓ | ✓ | ||||
| Wei, 2006 (38) | C-C | Taiwan | School-based urine screening program & questionnaire (92–97) | 0–18 | 260 | 87 | Randomly selected negatives from screening program | 533 | 88 | ✓ | ✓ | ✓ | ✓ | ✓(3) | |
| Tenconi, 2007 (39) | C-C | Italy | Pavia type 1 diabetes register (88–00) | 0–19 | 99 | 85 | Hospital (age, sex, week) | 194 | ? | ✓ | |||||
| Haynes, 2007 (40) | Cohort | Australia | W. Australian Children's Diabetes Register (80–02) | 0–14 | 926 | 99¶ | W. Australia Midwives' Notification System | ∼557,707 | NA | ✓ | ✓ | ✓ | ✓ | ||
| Ievins, 2007 (41) | Cohort | England | Hosp. admission [ICD diabetes code] (63–99) | 0–14 | 410 | — | Oxfordshire/W. Berkshire maternity records | 266,665 | NA | ✓ | ✓ | ✓ | ✓ | ✓ | ✓(any) |
| Borras Perez, 2007 (42) | C-C | Spain | Catalonia type 1 diabetes register (97–08) | 0–14 | 626 | 72 | Catalonia Public Health Birth Register | 3,320 | 98 | ✓ | ✓ | ✓(any) | |||
| Rosenbauer, 2008 (12) | C-C | Germany | Nationwide hosp. based surveillance (92–95) | 0–4 | 747 | 71 | Local registration offices (age, sex, area) | 1,820 | 43 | ✓ | ✓ | ✓§ | ✓(4) | ||
| Waldhoer, 2008 (43) | Cohort | Austria | Austrian diabetes register (89–05) | 0–5 | 444 | 85¶ | Birth certificate registry | 1,435,385 | NA | ✓ | ✓ | ✓ | |||
| First author, year* (reference) . | Design . | Country . | Type 1 diabetic subjects . | Control subjects . | Available confounders‡ . | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Ascertainment method (year case subjects diagnosed) . | Age at dx (years) . | n† . | Resp rate (%) . | Source (matching criteria) . | n† . | Resp rate (%) . | BO . | BW . | GA . | MD . | CS . | BF# (months) . | |||
| Dahlquist, 1992 (9) | C-C | Sweden | Swedish childhood diabetes register (78–88) | 0–14 | 2,757 | 98 | Medical birth registry (birth year, unit) | 8,271 | 100 | ||||||
| Bock, 1994 (10) | C-C | Denmark | Hosp. admission from National Patient Registry (78–89) | <16 | 837 | 98 | Birth registry (age, sex) | 837 | NA | ||||||
| Patterson, 1994 (11) | C-C | Scotland | Hosp. admission/childhood diabetes register (76–88) | 0–14 | 271 | 100 | Maternal discharge records (age, sex, area) | 1,340 | 100 | ✓ | ✓ | ✓ | ✓ | ✓ | ✓(any) |
| Wadsworth, 1997 (25) | C-C | U.K. | British Paediatric Association Surveillance Unit (92) | 0–5 | 213 | 89 | Health Authority Immunization Register | 318 | 70 | ✓ | ✓ | ✓ | ✓(4) | ||
| Gimeno, 1997 (26) | C-C | Brazil | Diabetes association/ Hospital admission (95) | 0–19 | 344 | 91 | Unclear (neighborhood, sex, age)‖ | 333 | 100 | ✓ | ✓ | ✓ | ✓(3) | ||
| McKinney, 1999 (28) | C-C | England | Yorkshire Childhood Diabetes Register (93–94) | 0–15 | 220 | 94 | General practitioner's records (age, sex) | 423 | 82 | ✓ | ✓ | ✓ | ✓ | ✓ | ✓(any) |
| Rami, 1999 (29) | C-C | Austria | Vienna type 1 diabetes register (89–94) | 0–14 | 103 | 86 | Schools (age, sex) | 373 | 80 | ✓ | ✓ | ✓ | ✓§ | ✓ | ✓(any) |
| Bache, 1999 (19)** | C-C | Denmark | Hospital admission (78–95) | 0–14 | 857 | 100 | Medical birth registry (month, sex, district) | 1,404 | 100 | ✓ | |||||
| Dahlquist, 1999 (14) | C-C | Bulgaria | W. Bulgaria type 1 diabetes register (91–94) | 0–14 | 125 | 73 | Schools and policlinics (age) | 440 | 79 | ✓ | ✓ | ✓ | ✓§ | ✓ | ✓(any) |
| C-C | Latvia | Latvian type 1 diabetes register (89–94) | 0–14 | 140 | 99 | Population register (age) | 301 | 79 | ✓ | ✓ | ✓ | ✓§ | ✓ | ✓(any) | |
| C-C | Lithuania | Lithuanian type 1 diabetes register (89–94) | 0–14 | 117 | 94 | Policlinics (age) | 266 | 73 | ✓ | ✓ | ✓ | ✓§ | ✓ | ✓(any) | |
| C-C | Luxembourg | Luxembourg type 1 diabetes register (89–95) | 0–14 | 59 | 100 | Preschools and schools (age) | 172 | 95 | ✓ | ✓ | ✓ | ✓§ | ✓ | ✓(any) | |
| C-C | Romania | Bucharest type 1 diabetes register (89–94) | 0–14 | 81 | 74 | Preschools and schools (age) | 277 | 81 | ✓ | ✓ | ✓ | ✓§ | ✓ | ✓(any) | |
| Stene, 2001 (13) | Cohort | Norway | Norwegian Childhood Diabetes Registry (89–98) | 0–14 | 1,810 | 100¶ | Norwegian medical birth registry | 1,382,602 | NA | ✓ | ✓ | ✓ | ✓ | ✓ | |
| Visalli, 2003 (30) | C-C | Italy | Lazio type 1 diabetes register (89–95) | 0–14 | 139 | 100 | Schools (age) | 703 | 91 | ✓ | ✓ | ✓ | ✓ | ✓(3) | |
| Stene, 2004 (31) | C-C | Norway | Norwegian Childhood Diabetes Registry (98–00) | 0–14 | 346 | 73 | Norwegian population registry | 1,626 | 56 | ✓ | ✓ | ✓ | ✓§ | ✓ | ✓(3) |
| Sadauskaite-Kuehne, 2004 (15) | C-C | Sweden | SE Sweden type 1 diabetes register (95–00) | 0–15 | 442 | 100 | Population register | 1,084 | 73 | ✓ | ✓ | ✓ | ✓§ | ✓(3) | |
| C-C | Lithuania | Lithuanian type 1 diabetes register (96–00) | 0–15 | 281 | 100 | Outpatient clinic‖ | 807 | 95 | ✓ | ✓ | ✓ | ✓§ | ✓(3) | ||
| Sumnik, 2004 (32) | C-C | Czech Republic | Czech Republic type 1 diabetes registry (95–00) | 0–15 | 640 | 79 | National Birth registry (age) | 32,000 | 100 | ✓ | |||||
| Marshall, 2004 (33) | C-C | England | Morecambe Bay/E. Lancashire diabetes clinics (98) | 0–15 | 196 | 83 | Health Authorities (sex, birth date) | 381 | 53 | ✓ | ✓ | ✓ | ✓§ | ✓(any) | |
| Cardwell, 2005 (34) | Cohort | N. Ireland | N. Ireland type 1 diabetes register (71–01) | 0–14 | 990 | 92¶ | Northern Ireland Child Health register | 439,647 | NA | ✓ | ✓ | ✓ | ✓ | ✓ | ✓(any) |
| Sipetić, 2005 (35) | C-C | Serbia | Belgrade Hospital admission (94–97) | 0–16 | 105 | 91 | Hospital outpatients with skin disease‖ (age, sex, area) | 210 | 100 | ✓ | ✓ | ✓ | ✓§ | ✓ | ✓(4) |
| Svensson, 2005 (36) | C-C | Denmark | Danish register of childhood diabetes (96–99) | 0–14 | 602 | 100 | Danish population register (age, sex) | 1,459 | 100 | ✓ | ✓ | ✓ | ✓ | ✓ | ✓(4) |
| Bottini, 2005 (20)** | C-C | Sardinia | Hospital diagnosis | ? | 189 | ? | Consecutive births in northern Sardinia | 5,460 | ? | ||||||
| Polańka, 2006 (37) | C-C | Poland | Upper Silesia Diabetes Register (89–96) | 0–14 | 394 | 87 | Central Bureau for Statistics | 994,460 | 100 | ✓ | ✓ | ||||
| Wei, 2006 (38) | C-C | Taiwan | School-based urine screening program & questionnaire (92–97) | 0–18 | 260 | 87 | Randomly selected negatives from screening program | 533 | 88 | ✓ | ✓ | ✓ | ✓ | ✓(3) | |
| Tenconi, 2007 (39) | C-C | Italy | Pavia type 1 diabetes register (88–00) | 0–19 | 99 | 85 | Hospital (age, sex, week) | 194 | ? | ✓ | |||||
| Haynes, 2007 (40) | Cohort | Australia | W. Australian Children's Diabetes Register (80–02) | 0–14 | 926 | 99¶ | W. Australia Midwives' Notification System | ∼557,707 | NA | ✓ | ✓ | ✓ | ✓ | ||
| Ievins, 2007 (41) | Cohort | England | Hosp. admission [ICD diabetes code] (63–99) | 0–14 | 410 | — | Oxfordshire/W. Berkshire maternity records | 266,665 | NA | ✓ | ✓ | ✓ | ✓ | ✓ | ✓(any) |
| Borras Perez, 2007 (42) | C-C | Spain | Catalonia type 1 diabetes register (97–08) | 0–14 | 626 | 72 | Catalonia Public Health Birth Register | 3,320 | 98 | ✓ | ✓ | ✓(any) | |||
| Rosenbauer, 2008 (12) | C-C | Germany | Nationwide hosp. based surveillance (92–95) | 0–4 | 747 | 71 | Local registration offices (age, sex, area) | 1,820 | 43 | ✓ | ✓ | ✓§ | ✓(4) | ||
| Waldhoer, 2008 (43) | Cohort | Austria | Austrian diabetes register (89–05) | 0–5 | 444 | 85¶ | Birth certificate registry | 1,435,385 | NA | ✓ | ✓ | ✓ | |||
*Year of publication.
†Number included in analysis of maternal age.
‡Tick denotes data recorded in study and available for analysis.
§Maternal type 1 diabetes used in analyses.
‖Not randomly selected and population based.
¶Percentage of case subjects identified in cohort.
#Duration of breast-feeding used in adjusted analysis shown in brackets.
**Only included in sensitivity analyses. dx, diagnosis; Resp, response; BF, breast-feeding (in months); BO, birth order; BW, birth weight; C-C, case-control; CS, cesarean section; GA, gestational age; Hosp., hospital; MD, maternal diabetes; NA, not applicable.