Annals of Internal Medicine, 2013 · n=903 · rct
Daily application of SPF 15+ broad-spectrum sunscreen reduced clinical skin aging by 24% (OR 0.76, 95% CI 0.59–0.98) over 4.5 years compared with discretionary use in the Nambour randomized trial; microtopography confirmed significantly less photoaging progression; Australian NHMRC-funded with no industry involvement