Table 1.
Characteristics of the skin screened sample from the population‐based cohort (RS) and a random sample of patients with AK from the GPs database (IPCI)
| Routine GP records (IPCI) | RS | ||
|---|---|---|---|
| N | 1000 | 1322 | |
| Male, n (%) | 471 (47) | 723 (55) | |
| Age, mean ± SD | 69 ± 12 | 61 ± 5 | |
| Number of AK, n (%) | Described by GPa,b | Counted during FBSE | Described by GP during 455 visitsa |
| 1–3 | 528 (53) | 724 (55) | 117 (26) |
| 4–9 | 27 (3) | 328 (25) | 5 (1) |
| > 10 | 2 (0·2) | 270 (20) | 0 (0) |
| Present, without absolute numbers | 412 (41) | 0 (0) | 333 (73) |
| History of cutaneous keratinocyte carcinoma, n (%) | 325 (25) | ||
| Basal cell carcinoma | 53 (5) | 271 (20) | |
| Squamous cell carcinoma | 23 (2) | 69 (5) | |
Basic characteristics of patients included in hospital claims data are not available as patient characteristics are not recorded in claims data on a nationwide level. AK, actinic keratosis; FBSE, full‐body skin examination; GP, general practitioner; IPCI, Integrated Primary Care Information; RS, Rotterdam Study. aBased on routine GP care, where FBSE is usually not conducted and the number of AK is usually not explicitly stated in GP records. bTotal number does not add up to 1000 as 31 patients ultimately did not have AK.