Vital-Sign Reference Values in Apparently Healthy African Adults: A Scoping Review of Physiological Evidence and Knowledge Gaps

This scoping review maps and synthesises the available physiological evidence on reference and normative values for major vital signs in apparently healthy African adults. It examines heart rate/pulse, blood pressure, respiratory rate, body temperature, and peripheral oxygen saturation (SpO₂), with particular attention to the availability of formal reference evidence, variation in reported values across physiological and measurement contexts, the measurement and statistical constructs used to characterise normative values, and important gaps in the African evidence base. Eligible evidence includes studies conducted in Africa involving healthy, apparently healthy, screened-reference, or relevant general-population adult samples that report formal reference limits, percentile distributions, prediction limits, or informative normative distributions for the vital signs of interest. This OSF registration is retrospective. The review had already commenced before registration, including literature searching and screening activities. The registration was created before submission of the manuscript to a journal and records the methods actually used in conducting the review. It should not be interpreted as an a priori preregistration or as implying that all methodological decisions were prespecified before searching or screening.