Comparação dos lipocalibradores Baseline® e Harpenden® para a medição de pregas cutãneas

Introduction: Ideally, all instruments for body composition assessment would be tested by comparison with a gold standard which is not always possible. In order to overcome this limitation the agreement with another instrument for which validity has been tested previously is frequently used. The aim of this study was to compare the measures obtained with a Baseline® calliper with the respective measures assessed with a Harpenden® calliper. Methods: We evaluated 68 participants, of both genders, with median age 27 years. Of the 58 women, 35 (60.3%) were pregnant. The instruments used were a Baseline® Skinfold Calliper - Aluminum and a Harpenden® calliper. Tricipital (TST) and subscapular (SST) skinfold thickness were measured. Measures with two instruments were compared by Wilcoxon test and their association was quantified by Spearman correlation coefficients. Bland & Altman diagrams were used to assess agreement between instruments. Results: The measurements obtained by the two callipers were significantly different for TST (median: 21.0 mm vs. 26.0 mm; p<0.001) and for SST (median: 17.7 mm vs. 21.5 mm; p<0.001), being higher when measured with Baseline® calliper. The median difference between the two measurements was 4.6 mm (interquartile range: 1.8-6.4) for TST and 3.1 mm (interquartile range: 1.7-5.4) for SST The difference between instruments was not influenced by skinfold thickness value neither by body mass index. According to Bland & Altman method, very large agreement limits were observed comparatively with the median value for skinfold thickness. The correlation between measurements with two instruments was 0.90 for TST and 0.95 for SST. Conclusion: We concluded that these two instruments can not be used interchangeably once, even maintaining measurement conditions, the two instruments conducted to different results. The differences between instruments are susceptible to originate big discrepancies in body fat estimation.