Background : Sun protection is a central dermatologic recommendation to decrease skin cancer risk, however an objective measure of sun protective adherence is lacking. Research relies upon self-reported measures such as the Sun Protection Habits Index (SPHI). Compliance with sun protection may place patients at risk for vitamin D deficiency and its associated adverse health outcomes. Due to lack of consensus among guidelines for adequate vitamin D levels and monitoring, serum testing and associated costs have increased exponentially across the past several decades.
Aims : Aim 1: To evaluate whether serum 25-hydroxyvitamin-D (25-OH-D) status (sufficient >32 ng/mL, versus deficient) acts as an objective measure of a SPHI <3.0 (sun protection non-adherence).
Aim 2: To evaluate whether the Health Professionals Follow-Up Study (HPFS) predictive 25-OH-D model can clinically categorize an individual's 25-OH-D level, obviating reliance on serum testing.
Methods : Survey information was collected from 214 English-speaking, adult, dermatology patients of the Emory Dermatology Clinics with known 25-OH-D levels from September 2008-November 2010. Exclusion criteria included medical conditions affecting 25-OH-D levels (e.g. intestinal malabsorption). Logistic regression evaluated whether sufficient 25-OH-D status predicted sun protection non-adherence (SPHI<3.0).
Published linear regression coefficients from the HPFS model were used to predict our sample's 25-OH-D levels. Cohen's kappa evaluated agreement between predicted and observed clinical categories of 25-OH-D level (sufficient, insufficient, deficient, severely deficient).
Results: In univariate logistic regression, the odds of non-adherence to sun protection among 25-OH-D sufficient (>32 ng/mL) patients were 0.53 times lower (95% CI: 0.29-0.99, p=0.049) than the odds among 25-OH-D deficient (≤32 ng/mL) patients. In multivariate logistic regression adjusting for skin cancer history, age, race and supplementation, the odds of non-adherence among sufficient patients were 0.64 times lower (95% CI: 0.33-1.25,p=0.26) than the odds among deficient patients.
Cohen's kappa for agreement between HPFS predicted and observed categories of 25-OH-D was 0.01 (95% confidence limits: -0.11-0.14).
Conclusions : Sufficient 25-OH-D levels were not associated sun protection non-adherence in multivariate logistic regression. Univariate logistic regression suggested that sufficient 25-OH-D status was associated with sun protection adherence.
There was no more than chance agreement between HPFS model predicted and observed clinical categories of 25-OH-D status.
Table of Contents
TABLE OF CONTENTS
a. Tables 1-18
b. Figure 1
About this Master's Thesis
|Committee Chair / Thesis Advisor|
|Sun Protection Adherence and Vitamin D Levels Among Dermatology Patients ()||2018-08-28||