Reference intervals for common biochemistry laboratory tests in the Saudi population by a direct a priori method

BACKGROUND: Reference intervals (RI) for biochemistry laboratory tests are now based on Caucasian rather than Saudi populations. Test parameters may vary because of race, lifestyle, population structure and geographic location. OBJECTIVES: To establish reference intervals for common clinical chemistry laboratory tests for the Saudi population. DESIGN: Direct a priori method. SETTING: Tertiary care hospital. MATERIALS AND METHODS: Blood samples were taken from 625 individuals aged from 2 to 87 years from different geographic areas for 93 biochemistry tests. RIs were established following the International Federation of Clinical Chemistry guideline. MAIN OUTCOME MEASURE(S): Reference values for common biochemistry lab tests. RESULTS: Ninety-three age- or gender-stratified reference intervals (RIs) based on the Saudi population were established. There were 72 non-partitioned tests. Most of the tests were similar to RIs from manufacturer’s inserts. For some sex hormones (estrogen, luteinizing hormone, follicle-stimulating hormone, progesterone and 17α-Hydroxyprogesterone) only male RIs were established as there were not enough samples to stratify for females based on physiologic status. CONCLUSION: The RIs are reliable and applicable to a general Saudi population. LIMITATIONS: Due to the sample size, RIs were not generated for some sex hormones for females.