title: Sunburn, sun exposure, and sun sensitivity in the Study of Nevi in Children.
abstract: OBJECTIVE
  To examine the joint effect of sun exposure and sunburn on nevus counts (on the natural logarithm scale; log nevi) and the role of sun sensitivity.
  
  
  METHODS
  We describe an analysis of cross-sectional data from 443 children enrolled in the prospective Study of Nevi in Children. To evaluate the joint effect, we partitioned the sum of squares because of interaction between sunburn and sun exposure into orthogonal components representing (1) monotonic increase in log nevi with increasing sun exposure (rate of increase of log nevi depends on sunburn), and (2) nonmonotonic pattern.
  
  
  RESULTS
  In unadjusted analyses, there was a marginally significant monotonic pattern of interaction (P = .08). In adjusted analyses, sun exposure was associated with higher log nevi among those without sunburn (P < .001), but not among those with sunburn (P = .14). Sunburn was independently associated with log nevi (P = .02), even though sun sensitivity explained 29% (95% confidence interval: 2%-56%, P = .04) of its effect. Children with high sun sensitivity and sunburn had more nevi, regardless of sun exposure.
  
  
  CONCLUSIONS
  A program of increasing sun protection in early childhood as a strategy for reducing nevi, when applied to the general population, may not equally benefit everyone.
authors.affiliation: Department of Epidemiology and Biostatistics, Memorial Sloan Kettering Cancer Center, New York, NY. Electronic address: satagopj@mskcc.org.
authors.forename: Jaya M
authors.initials: JM
authors.lastname: Satagopan
authors.affiliation: Department of Epidemiology and Biostatistics, Memorial Sloan Kettering Cancer Center, New York, NY; Dermatology Service, Department of Medicine, Memorial Sloan Kettering Cancer Center, New York, NY.
authors.forename: Susan A
authors.initials: SA
authors.lastname: Oliveria
authors.affiliation: Department of Epidemiology and Biostatistics, Memorial Sloan Kettering Cancer Center, New York, NY.
authors.forename: Arshi
authors.initials: A
authors.lastname: Arora
authors.affiliation: Dermatology Service, Department of Medicine, Memorial Sloan Kettering Cancer Center, New York, NY.
authors.forename: Michael A
authors.initials: MA
authors.lastname: Marchetti
authors.affiliation: Department of Epidemiology and Biostatistics, Memorial Sloan Kettering Cancer Center, New York, NY.
authors.forename: Irene
authors.initials: I
authors.lastname: Orlow
authors.affiliation: Dermatology Service, Department of Medicine, Memorial Sloan Kettering Cancer Center, New York, NY.
authors.forename: Stephen W
authors.initials: SW
authors.lastname: Dusza
authors.affiliation: Dermatoepidemiology Unit, VA Medical Center, Providence, RI; Department of Dermatology, Rhode Island Hospital, Providence, RI; Department of Dermatology, Brown University, Providence, RI; Department of Epidemiology, Brown University, Providence, RI.
authors.forename: Martin A
authors.initials: MA
authors.lastname: Weinstock
authors.affiliation: Dermatology Service, Department of Medicine, Memorial Sloan Kettering Cancer Center, New York, NY; Department of Dermatology, Sheba Medical Center and Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel.
authors.forename: Alon
authors.initials: A
authors.lastname: Scope
authors.affiliation: Department of Social and Behavioral Sciences, Harvard School of Public Health, Boston, MA.
authors.forename: Alan C
authors.initials: AC
authors.lastname: Geller
authors.affiliation: Dermatology Service, Department of Medicine, Memorial Sloan Kettering Cancer Center, New York, NY.
authors.forename: Ashfaq A
authors.initials: AA
authors.lastname: Marghoob
authors.affiliation: Dermatology Service, Department of Medicine, Memorial Sloan Kettering Cancer Center, New York, NY.
authors.forename: Allan C
authors.initials: AC
authors.lastname: Halpern
mesh_terms: D002648:Child; D002675:Child, Preschool; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D008297:Male; D008404:Massachusetts / Q000453:epidemiology; D009506:Nevus; D011446:Prospective Studies; D012044:Regression Analysis; D012307:Risk Factors; D012878:Skin Neoplasms / Q000453:epidemiology*; D013471:Sunburn; D013472:Sunlight; D011795:Surveys and Questionnaires; D014466:Ultraviolet Rays / Q000009:adverse effects*
keywords: Proportion of effect explained; Regression; Statistical interaction; Sun protection; Ultraviolet radiation