Table 1.
Characteristics of included studies.
| Study | Country | Study period | Study design | Cases (events/total) | Controls (events/total) | Study population | Matched control group |
|---|---|---|---|---|---|---|---|
| Cases group for Parkinson’s diseases | |||||||
| Rugbjerg et al. (13) | Denmark | 1986-2006 | Case-control study | Total (13695); IBD (52), CD (10), UC (42); SS (2); SLE (3); MS (7); RA (63); GD (22); CLD (2); MG (2); PM (2); scleroderma (4); Addison disease (2); AIHA (2); PA (21); PBC (2) | Total (68445); IBD (193), CD (47), UC (146); SS (20); SLE (20); MS (72); RA (456); GD (82); CLD (9); MG (12); PM (7); scleroderma (5); Addison disease (14); AIHA (7); PA (89); PBC (7) | The Danish National Hospital Register | Matched 5 controls to each case based on year of birth and sex |
| Hsu et al. (20) | China | 2000-2008 | Retrospective cohort study | IBD (37/1698) | IBD (133/6792) | The National Health Research Institutes (NHRI) | Matched 4 controls to each case based on age and sex |
| Wu et al. (17) | China | 2000-2010 | Case-control study | SS (143/7716) SLE (22/7716) |
SS (893/75129) SLE (173/75129) |
Longitudinal Health Insurance Database (LHID) and National Health Institutes Research Database (NHIRD) | Matched 10 controls to each case based on age, gender and index date |
| Camacho-Soto et al. (21) | USA | 2004-2009 | Case-control study | IBD (2599/89790) CD (749) UC (1583) |
IBD (2381/118095) CD (708) UC (1405) |
Medicare base file (BASF) | Controls were a random sample of remaining beneficiaries |
| Bacelis et al. (22) | Sweden | 1964-2016 | Case-control study | RA (68/8256) | RA (1126/82452) | Socialstyrelsen (SOS), a Swedish governmental agency managing medical registries | Matched 10 controls to each case based on birth year, sex, birth location, and time of follow-up |
| Paakinaho et al. (23) | Finland | 1996-2015 | Case-control study | RA (315/1571) | NA | The Finnish Parkinson’s disease (FINPARK) cohort | Matched on age, sex, and region of residence |
| Cases group for autoimmune diseases | |||||||
| Ludvigsson et al. (24) | Sweden | 1964-2003 | Retrospective cohort study | CLD (26/14345) | CLD (139/69958) | The Swedish National Board of Health and Welfare used the Swedish national inpatient register (IPR) | Matched on age, sex, calendar year and county |
| Taghipour et al. (25) | UK | 2004-2008 | Case-control study | BP (4/90) | BP (3/141) | Specialist outpatient center for immunobullous diseases at a teaching hospital in Oxford, England | Matched on age and sex |
| Bastuji-Garin et al. (26) | France | 2003-2007 | Case-control study | BP (28/201) | BP (20/345) | 11 dermatology departments (11 hospitals) in France | Matched on age, gender, center, and place of residence |
| Chen et al. (27) | China | 1997-2008 | Case-control study | BP (416/3489) | BP (658/17425) | National Health Insurance Research Database (NHIRD) and Longitudinal Health Insurance Database 2000 (LHID 2000) | Matched 5 controls to each case based on age and sex |
| Langan et al. (28) | UK | 1996-2006 | Case-control study | BP (26/868) | BP (36/3453) | The Health Improvement Network database | Matched 4 controls to each case based on age and sex |
| Li et al. (12) | Sweden | 1964-2007 | Retrospective cohort study | CD (13/22750), UC (46/27881); SS (5/1360); SLE (8/5677); T1D (2/21946); MS (23/12503); RA (132/52994); GD (166/34735); BD (10/2718); CLD (6/10544); MG (7/2479); PM (2/1417); scleroderma (2/712); Addison disease (1/1841); AIHA (2/830); PA (56/5617); PBC (4/1379) | General population | The Primary Health Care Research Center-MigMed Database, Lund University | Sweden age and sex specific general population incidence rates for PD |
| Brick et al. (29) | USA | 1960-2009 | Case-control study Retrospective cohort study |
BP (3/87) BP (4/84) |
BP (1/261) BP (2/251) |
Databases of the Rochester Epidemiology Project | Matched 3 controls to each case based on age and sex |
| Nielsen et al. (30) | Denmark | 1977-2011 | Prospective cohort study | MS (26/15557) | General population | Danish Multiple Sclerosis Registry (DMSR) | Corresponding national sex-, age- and period-specific incidence rates for pd in the Danish population |
| Teixeira et al. (31) | Portugal | 1998-2010 | Case-control study | BP (2/77) | BP (4/176) | Coimbra University Hospital | Matched 2 controls to each case based on age and sex |
| Klimek et al. (32) | Austria | 2006-2007 | Retrospective cohort study | T1D (N/16667) | T1D (N/1862258) | Database of the Main Association of Austrian Social Security Institutions | The total sample of inpatients |
| Liu et al. (33) | China | 2000-2010 | Prospective cohort study | SLE (55/12817) | SLE (393/51268) | The National Health Insurance Research Database (NHIRD) | Matched 2 controls to each case based on age and sex |
| Lin et al. (34) | China | 2000-2011 | Retrospective cohort study | IBD (106/8373) CD (97) UC (9) |
IBD (290/33492) | Health Insurance Database 2000 (LHID 2000) | Matched 4 controls to each case based on age and sex |
| Sung et al. (2016) (35) | China | 1998-2010 | Retrospective cohort study | RA (360/33221) | RA (2381/132884) | Catastrophic Illness Patient Database (RCIPD) | Matched 4 controls to each case based on age and sex |
| Thormann et al. (36) | Denmark | 1980-2005 | Prospective cohort study | MS (34/8947) | MS (73/44733) | Danish Multiple Sclerosis Registry (DMSR) | Matched 5 controls to each case based on age, sex and municipality |
| Bählera et al. (37) | Switzerland | 2014 | Cross-sectional study | IBD (72/4197) | IBD (5184/1114638) | The Helsana Insurance Group | The helsana insurance group without IBD |
| Daneshpazhooh et al. (38) | Iran | 2006-2011 | Case-control study | BP (4/160) | BP (7/317) | Autoimmune Bullous Diseases Research Center, Razi Hospital, Tehran | Matched 2 controls to each case based on age and sex |
| Khosravani et al. (39) | Iran | 2001-2016 | Cross-sectional study | BP (3/87) | BP (4/184) | Faghihi Hospital, Shiraz, Iran | Matched 2 controls to each case based on age and sex |
| Kibsgaard et al. (40) | Denmark | 1977-2015 | Prospective cohort study | BP (78/3281) | BP (352/32213) | The Danish National Patient Registry (DNPR) | Matched 10 controls to each case based on age and sex |
| Sim et al. (41) | Singapore | 2005-2014 | Case-control study | BP (15/105) | BP (4/315) | Department of Dermatology, Singapore General Hospital | Matched 3 controls to each case based on age and sex |
| Yu Phuan et al. (42) | Singapore | 2010-2015 | Case-control study | BP (18/103) | BP (7/103) | Tan Tock Seng Hospital, Singapore | Matched on age and sex |
| Chang et al. (14) | China | 2001-2012 | Retrospective cohort study | SS (215/8422) SLE (49/3055) RA (379/19542) |
SS (2285/138424) SLE (2285/138424) RA (2285/138424) |
National Health Insurance Research Database (NHIRD) | Matched on age and sex |
| Jeon et al. (43) | South Korea | 2006-2013 | Case-control study | BP (6/103) | General population | Chonnam National University Hospital (CNUH) in Gwangju | Age-matched general population |
| Kridin et al. (44) | Israel | 2004-2014 | Cross-sectional study | BP (175/1985) | BP (437/9874) | Clalit Health Services (CHS) database | Matched 5 controls to each case based on sex, age, and ethnicity |
| Peter et al. (45) | USA | 2000-2016 | Retrospective cohort study | IBD (371/144018), CD (122/56507), UC (243/84436) |
IBD (1425/720090) CD (480) UC (913) |
The truven health marketscan commercial database and the medicare supplemental database | Matched 5 controls to each case based on age and sex |
| Villumsen et al. (15) | Denmark | 1997-2014 | Retrospective cohort study | IBD (335/76477) | IBD (39784/7548295) | The danish national patient register (NPR) | Matched on sex, age and vital status |
| Chen et al. (16) | China | 2000-2012 | Retrospective cohort study | SS (44/4053) | SS (13/4053) | The longitudinal health insurance database 2000 (LHID2000) | Matched 1 controls to each case based on age, sex and comorbidities |
| Ju et al. (46) | China | 2000-2010 | Retrospective cohort study | SS (159/12640) | SS (452/50560) | The National Health Insurance Research Database (NHIRD) | Matched 4 controls to each case based on age and sex |
| Papakonstantinou et al. (47) | Germany | 2011-2015 | Case-control study | BP (9/183) | BP (6/348) | Clinic in Germany | Matched on age and sex |
| Park et al. a (48) | South Korea | 2010-2013 | Retrospective cohort study | IBD (92/38861) CD (15/12631) UC (77/26230) |
IBD (134/116583) CD (19/37893) UC (115/78690) |
The national health insurance service (NHIS) | Matched 3 controls to each case based on age and sex |
| Park et al. b (49) | South Korea | 2010-2013 | Prospective cohort study | BD (50/11525) | BD (51/34575) | Korean national health insurance service (NHIS) | Matched 3 controls to each case based on age and sex |
| Weimers et al. (50) | Sweden | 2002-2014 | Prospective cohort study | IBD (103/39652) CD (23/11428) UC (69/24422) |
IBD (1556/396520) | The swedish national patient register (NPR) | Matched 10 controls to each case based on sex, age, calendar year, and place of residence |
| Hsu et al. (51) | China | 2000-2014 | Retrospective cohort study | SS (273/17028) | SS (798/68094) | National Health Insurance (NHI) Research Database (NHIRD) | Matched 4 controls to each case based on gender, age group, and comorbidities |
| Noh et al. (52) | South Korea | 2002-2006 | Retrospective cohort study | IBD (25/411) | IBD (55/1405) | The nationwide administrative claims-based database of the national health insurance service (NHIS) | NA |
| Coates et al. (53) | USA | 2005-2014 | Retrospective cohort study | IBD (68/154051) CD (35) UC (33) |
IBD (64/154051) CD (26) UC (38) |
The marketscan commercial claims and encounters database | Matched 1 controls to each case based on age |
| Kridin et al. (2021) (54) | Germany | 2008-2011 | Cross-sectional study | BP (129/1743) | BP (292/10141) | Computerized data set of techniker krankenkasse | Matched 6 controls to each case based on age and sex |
| Kronzer et al. (55) | USA | 2009-2020 | Case-control study | RA (44/821) | RA (182/2455) | Mayo Clinic Biobank | Matched 3 controls to each case based on age, sex, recruitment year, and location |
| Sayar et al. (56) | Turkey | 1987-2021 | Case-control study | BP (3/145) | BP (5/310) | Department of Dermatology of the Istanbul Faculty of Medicine | Matched on age and sex |
| Cho et al. (57) | South Korea | 2009-2014 | Prospective cohort study | GD (301/65380) | GD (1097/326900) | National Health Information Database (NHID) | Matched 5 controls to each case based on age and sex |
| Kim et al. (58) | South Korea | 2011-2017 | Prospective cohort study | IBD (98/24830) CD (12/4454) UC (86/20376) |
IBD (256/99320) | The National Health Insurance Service (NHIS) | Matched 4 controls to each case based on age and sex |
| Kwon et al. (59) | South Korea | 2010-2017 | Retrospective cohort study | MS (21/1380) | MS (14/6900) | The Korean National Health Insurance Service | Matched 5 controls to each case based on age, sex, hypertension, diabetes and dyslipidaemia |
NA, not applicable.