Table 1 Basic characteristics of 262 patients in the Swedish National Patient Register included in the review

No. of reviewed patients

262

No. females/males (%)

119 (45)/143 (55)

Mean age (range) at first validated procedure code

38 (14–74)

No. of hospitals included

27

Mean patient chart coverage (years)

5.4

No. of patients with surgical procedures validated

53

No. of separate surgical occasions validated

103

No. of surgical procedure codes validated

155

Mean no. of surgical procedure codes (SD) per hospital

6.1 (13.2)

Mean no. of surgical procedure codes (SD) per patient

3.1 (4.5)

Mean no. of surgical sessions (SD) per patient

1.9 (2.6)