Baseline characteristics of the study cohort in 12 months before the index date
| Characteristics | SID* | Inflammatory bowel disease | Psoriasis | Rheumatoid arthritis | Systemic lupus erythematous | Non-SID* |
|---|---|---|---|---|---|---|
| N | 133 333 | 25 176 | 34 665 | 58 979 | 14 513 | 533 332 |
| Percentage or mean±SD | ||||||
| Follow-up period, years | 2.1±1.8 | 2.1±1.9 | 2.0±1.8 | 2.1±1.8 | 2.0±1.8 | 2.1±1.9 |
| Age, years | 50.3±11.8 | 47.5±12.0 | 49.0±11.8 | 53.0±11.3 | 47.7±10.8 | 50.3±11.8 |
| HPV infection-associated factors | ||||||
| Sexually active | 63 | 68 | 61 | 60 | 76 | 54 |
| Oral contraceptives | 11 | 16 | 12 | 9 | 9 | 10 |
| Non-oral contraceptives | 1 | 2 | 1 | 1 | 1 | 1 |
| Smoking | 9 | 10 | 10 | 8 | 11 | 10 |
| Sexually transmitted diseases | 3 | 3 | 3 | 3 | 5 | 3 |
| Substance abuse | 0.5 | 1 | 0.4 | 0.4 | 1 | 0.5 |
| Alcoholism | 0.4 | 0.4 | 0.5 | 0.3 | 0.3 | 0.5 |
| Receipt of HPV vaccine | 0.3 | 0.3 | 0.4 | 0.3 | 0.3 | 0.5 |
| Comorbidities | ||||||
| Comorbidity score† Median (IQR) | 0.3±1.2 0 (0–1) | 0.5±1.2 0 (0–1) | 0.2±0.9 0 (0–0) | 0.3±1.1 0 (0–1) | 0.7±1.5 0 (0–1) | −0.3±1.2 −1 (−1–0) |
| Diabetes | 11 | 8 | 12 | 12 | 10 | 21 |
| Chronic kidney disease | 3 | 2 | 1 | 2 | 11 | 2 |
| Liver disease | 5 | 5 | 4 | 4 | 6 | 3 |
| Prior abnormal Pap smears | 4 | 5 | 4 | 3 | 5 | 3 |
| Medication | ||||||
| Systemic immunosuppressive drugs‡ | 35 | 13 | 20 | 57 | 21 | 1 |
| Systemic steroids | 38 | 27 | 17 | 52 | 46 | 14 |
| Cumulative steroid dose§, Median (IQR) | 387.5 (940.2) 0 (0–300) | 327.0 (928.7) 0 (0–105) | 77.6 (333.4) 0 (0–0) | 527.0 (1018.3) 105 (0–605) | 665.5 (1324.1) 0 (0–750) | 52.0 (299.9) 0 (0–0) |
| NSAIDs | 33 | 20 | 26 | 58 | 39 | 22 |
| Healthcare use | ||||||
| No of total doctor visits, Median (IQR) | 9.6±7.0 8 (5–12) | 8.5±6.5 7 (4–11) | 8.0±6.1 7 (4–10) | 10.5±7.1 9 (6–14) | 11.3±8.1 9 (6–15) | 6.7±5.2 5 (3–9) |
| No of visits to a gynaecologist, Median (IQR) | 0.8±1.9 0 (0–1) | 1.1±2.1 0 (0–1) | 0.9±2.0 0 (0–1) | 0.6±1.5 0 (0–1) | 1.0±2.6 0 (0–1) | 0.8±2.3 0 (0–1) |
| No of emergency room visits, Median (IQR) | 0.6±2.9 0 (0–0) | 0.7±3.1 0 (0–0) | 0.6±3.0 0 (0–0) | 0.5±2.6 0 (0–0) | 0.7±3.0 0 (0–0) | 0.5±2.6 0 (0–0) |
| No of prescription drugs, Median (IQR) | 9.8±6.6 9 (5–13) | 9.3±6.4 8 (5–12) | 8.5±6.0 7 (4–11) | 10.6±6.6 9 (6–14) | 11.2±7.3 10 (6–15) | 7.8±5.6 7 (4–11) |
| Acute hospitalizations | 16 | 24 | 10 | 14 | 23 | 15 |
| Preventive medical services | ||||||
| Pap smears | 44 | 50 | 45 | 40 | 44 | 41 |
| HPV DNA tests | 7 | 8 | 8 | 5 | 8 | 6 |
| Mammograms | 43 | 42 | 42 | 44 | 40 | 41 |
| Fecal occult blood tests | 12 | 13 | 12 | 12 | 11 | 11 |
| Serum cholesterol tests | 41 | 39 | 43 | 41 | 42 | 59 |
| Sigmoidoscopy/colonoscopy | 16 | 51 | 7 | 8 | 9 | 7 |
*SID and non-SID cohorts are age- and index date-matched.
†The range of combined comorbidity score is −2 to 26.
‡Systemic immunosuppressive drugs include azathioprine, cyclophosphamide, ciclosporin, hydroxyurea, leflunomide, methotrexate, 6-mercaptopurine, mycophenolate, pimecrolimus, tacrolimus, abatacept, adalimumab, alefacept, anakinra, certolizumab pegol, etanercept, golimumab, infliximab, rituximab, tocilizumab and ustekinumab.
§Cumulative steroid dose equivalent to prednisone was calculated over the 365-day baseline period.
HPV, human papillomavirus; NSAIDs, non-steroidal anti-inflammatory drugs; Pap, Papanicolaou; SID, systemic inflammatory disease.