Ref (type)	Population	Outcome, Interventions	Results and statistical analysis	Effect size	Favours
Incidence of actinic (solar) keratosis
RCT	588 people with previous solar keratoses, aged over 40 years, living in Victoria, Australia	Mean number of new lesions per person 7 months 1.6 with daily sunscreen use (sun protection factor [SPF] 17) 2.3 with placebo (base cream with no active ingredient)	RR 0.62 95% CI 0.54 to 0.71	Small effect size	daily sunscreen use