[Reference intervals for anemia-related routine blood test indicators in Hainan oldest-old and Hainan centenarians]

Objective: To investigate reference intervals for anemia-related routine blood test indicators in Hainan oldest-old and Hainan centenarians. Methods: A cross-sectional data set of China Hainan Centenarians Cohort Study (CHCCS) was used. Household interview, physical examinations, and blood sample analysis were conducted in accordance with standardized procedures. The hemoglobin level, red blood cell count, and hematocrit were analyzed with automatic biochemical analyzer and the reference intervals were determined following CLSI C28-A3 guidelines using a non-parametric method. Results: A total of 715 centenarians, including 137 males (19.2%), and 767 long-lived individuals aged ≥80 years, including 312 males (40.7%), were surveyed. The reference interval of hemoglobin level was 89.1-173.5 g/L in males and 94.4-146.0 g/L in females, respectively, in long-lived individual group. The reference interval of hemoglobin level was 68.4-145.6 g/L in males and 81.0-140.0 g/L in females, respectively, in centenarian group. Conclusion: The reference intervals of hemoglobin level, red blood cell count, and hematocrit were set for the first time for the oldest-old and centenarians in Hainan, which was lower than that currently used in adults.