Abstract
BACKGROUND: Serum ferritin (SF) test has been widely used in clinical practice. However, its reference intervals (RIs) vary depending on the analytical method and ethnic origin. This study was to establish the RIs using indirect method for SF in Chinese adults. METHODS: SF was assayed on Abbott i2000(SR) analyzer. The SF test results of all health examinees (8913 males aged 18-93 years and 5397 females aged 18-90 years) between December 2010 and April 2019 were obtained from our laboratory information system. After Box-Cox transformation of raw data and exclusion of outliers, parametric and non-parametric approaches were used to calculate 95% RIs. The correlation between SF levels and ages, and the differences in SF levels between subgroups were also analyzed. RESULTS: SF levels in females were significantly different from those in males (Z = 88.96, Z* = 23.17; Z > Z*) and showed a weak positive correlation with age (r = .466, P < .0001). The RIs based on parametric approach in males were 66.12-561.58 µg/L, whereas in all females were 3.59-269.59 µg/L, females aged <50 years 3.26-148.02 µg/L and those aged ≥50 years 17.28-303.27 µg/L. The RIs based on non-parametric approach in males were 65.00-571.37 µg/L whereas in all females were 4.00-254.00 µg/L, females aged <50 years 4.00-152.00 µg/L and those aged ≥50 years 16.00-304.05 µg/L. CONCLUSIONS: Our indirect RIs for SF were markedly different from the manufacturer's recommended RIs and might be more suitable for Chinese adults, which would be helpful in interpreting laboratory data and clinical decision-making.