Reliability and validity of a brief questionnaire to assess calcium intake in female collegiate athletes.

Abstract

Calcium intake often is inadequate in female collegiate athletes, increasing the risk for training injuries and future osteoporosis. Thus, a brief and accurate assessment tool to quickly measure calcium intake in athletes is needed. We evaluated the reliability and validity, compared to 6 days of diet records (DRs), of the Rapid Assessment Method (RAM), a self-administered calcium checklist. Seventy-six female collegiate athletes (mean age = 18.8 yrs, range= 17- 21; 97 % Caucasian) were recruited from basketball, cross-country, field hockey, soccer, and volleyball teams. Athletes completed a RAM at the start of the training season to assess calcium intake during the past week. Two weeks later, a second RAM was completed to assess reliability, and athletes began 6 days of diet records (DRs) collection. At completion of DRs, athletes completed a final RAM, corresponding to the same time period as DRs, to assess agreement between the 2 instruments. The RAM demonstrated adequate test-retest reliability over 2 weeks (n= 56; Intraclass correlation [ICC] = 0.54, p < 0.0001) and adequate agreement with DRs (n = 34; ICC = 0.41, p = 0.0067). Calcium intake was below recommended levels, and mean estimates did not differ significantly on the RAM (823 +/- 387 mg/d) and DRs (822 +/- 330 mg/d; p = 0.988). Adequacy of calcium intake from both DRs and the RAM was classified as "inadequate" (<1000 mg/d) and "adequate" (> or = 1000 mg/d). Agreement between the RAM and DRs for adequacy classification was fair (ICC= 0.30, p = 0.042), with the RAM identifying 84% of athletes judged to have inadequate calcium intake based on DRs. The RAM briefly and accurately estimates calcium intake in female collegiate athletes compared to DRs.