Number of patients in each cohort, number with skin cancer, and adjusted ratio of the rate of skin cancer in each cohort relative to that in the reference cohort (with 95% confidence intervals on the rate ratio)
| Cohort (ICD code) | Number of people | Average age (y) | Average follow up (y) | Total person years | Number with skin cancer | Adjusted rate ratio* | 95% Confidence interval | p Value |
|---|---|---|---|---|---|---|---|---|
| *Adjusted for age in five year bands, sex, district of residence and calendar year. †International Classification of Diseases codes, ninth revision: acute respiratory infections (460–6), dental treatment (520–1), deflected nasal septum, nasal polyp 470, 471), inguinal hernia (550), diseases of nail (703), sebaceous cyst (706.2), internal derangement of knee (717), bunion (727.1), selected fractures, dislocations, sprains and strains (810–6, 823–6, 830–9, 840–8), superficial injury and contusion (910–24), otitis externa, otitis media (380–2), haemorrhoids (455); and Office of Population Census and Surveys operation codes, fourth revision: appendicectomy (H01–3) tonsillectomy, adenoidectomy (E20, F24, F36), hip, knee arthroplasty (W37–42). ‡See text for ICD codes. §Diabetes (250), rheumatoid arthritis (714), inflammatory bowel disease (555–6); restricted to those aged 15–64 at admission because of large numbers of elderly people with these diseases. ¶Stroke (430–8), motor neurone disease (335), other neurological diseases (330, 333–4, 341, 344–348); restricted to those aged 15–64 at admission because of large numbers of elderly people with these diseases. | ||||||||
| Main comparison | ||||||||
| Reference cohort† | 432091 | 45 | 11.3 | 4876672 | 2284 | 1 | – | – |
| Multiple sclerosis‡ | 5004 | 46 | 10.2 | 51032 | 10 | 0.49 | 0.24 to 0.91 | 0.03 |
| Other comparisons | ||||||||
| Autoimmune conditions§ | 39831 | 46 | 10.4 | 414932 | 193 | 1.06 | 0.91 to 1.24 | 0.45 |
| Diseases of central nervous system¶ | 27274 | 50 | 8.1 | 219863 | 125 | 1.01 | 0.83 to 1.22 | 0.95 |