Validating the Selection Process of Healthy Control Group Based on Apparently Healthy Volunteers

Abstract

Objectives: The objective of this cross sectional study is to evaluate the probability of finding healthy control subjects according to the results of multiple lab tests in multiple domains including biochemical hematological and immunological measurements.
Material and methods: During the period March- June 2016 a sample of 217 apparently healthy Iraqi adults were investigated whether or not they satisfactorily meet the criteria accomplishing the reality of being healthy. Blood specimens were collected from each participant using standard procedures. The following measurements and tests were carried out for all studied participants: anthropometric measurements, complete blood picture test, enzymatic colorimetric assay for serum lipid profile, glucose, urea, creatinine, alanine transferase, and Enzyme Linked Immunosorbent Assay (ELISA) for serum high sensitive C reactive protein and interleukin 1 beta.
Results: The prevalence rates (PR) of apparently healthy individuals (AHI) were in descending order of wellness requirements as follow: in those with a completely normal lipid profile it was 25.3%, for biochemistry domain 31.3%, for white blood cell count domain 57.2%, for red blood cell count (RBC) domain 11.5% and for platelets domain tests it was 31.3%. A completely normal hematologic domain tests was found in only 8.8% of tested individuals, while for immunologic domain 9.2%. The probability of finding a normal control subject based on multiple testing domains was as low as 13.4%.
Conclusions: Avery considerable proportion of population who appear to be healthy, are not in reality, accordingly not all apparently healthy controls are qualified as eligible control. The really healthy control subject is of low probability (13.4%) among Iraqi apparently healthy adults. The WBC domain ranked at the top of restriction normality pyramid, followed by biochemistry, lipid profile, RBC domain and immunological domain respectively.