Session: SUN 257-280-Disorders of Vitamin D Metabolism & Action
Poster Board SUN-263
Methods: We performed retrospective chart review to compare subjects excluded (OUT) to those included (IN) in RCT. The main inclusion criteria were hemoglobin A1C (A1C) 5.7-6.9%, body mass index (BMI) 28-39kg/m2, 25-hydroxyvitamin D (25OHD) 5-29ng/ml, and the main exclusions were known T2DM, and serious disease that may interfere with participation or increase risk of side effects. Evaluation of effectiveness vs efficacy of the trial was performed using Pragmatic-Explanatory Contiuum Indicator Summary (PRECIS)1 tool completion for all 10 domains on a 10 point scale, by 16 endocrinology section members after discussion of the trial methodology. Scores near 0 favor efficacy research (i.e. ideal environment) while scores near 10 favor effectiveness research (i.e. practical setting)2.
Results: Subjects (n=356) had the same demographics (mean [SD]): AAM, Age 59 years. The OUT (n=178) vs IN (n=178) group had lower A1C (%) 5.8[0.5] vs 6.1[0.2], p<0.01. The level of 25OHD was similar (ng/ml) 15.2[5.5] vs 14.3[5.1], p=0.88. There was significant difference for LDL(mg/dl) 97.3 [31.2] vs 111.9 , HDL (mg/dl) 51.3[13.9] vs 44.6[10.1], and Charlson Index3 2.8[1.6] vs 2.2[1.13] for OUT and IN groups respectively. There were no differences for other measures: eGFR, cholesterol, triglycerides, proportion of HTN, DJD, CVD (including MI, stroke, PVD, and CHF), cancer (all combined), and psychiatric problems (including PTSD, depression, schizophrenia, and substance abuse). Subgroup analysis of subjects with A1C 5.7-6.9% (OUT n=105, IN n=178) showed significantly more cancer and less psychiatric disease and thiazide diuretic use for OUT vs IN. PRECIS data for all 16 participants (mean [SD]) was 7.7[0.67].
Discussion:Our analysis shows that RCT, an accepted gold standard for evidence-based advice, has clinically relevant limitations. Although the notion exists that RCT involves highly selected patients, the comparison of included and excluded subjects is rarely done or reported in the literature. RCT vary in their pragmatism which is important for physicians to understand regarding limitations of generalizing results to patients seen in clinical practice.
Conclusion: Patients included and excluded from this RCT differ by several important clinical characteristics. Advice based on the evidence from this RCT may not be applicable to all patients with the same demographics and disease seen in a clinical practice, although study design favors pragmatic applicability.
Nothing to Disclose: YE, AA, BM, HM, SCK, EB
*Please take note of The Endocrine Society's News Embargo Policy at http://www.endo-society.org/endo2013/media.cfm
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