ABSTRACT
Medical factors can be broadly classified into: (i) etiological factors that give rise to risk factors; (ii) risk factors that promote or inhibit a health condition; (iii) diagnostic factors that help to identify the presence or absence of a disease; (iv) treatment modalities that aim to alleviate suffering and bring the patient back to health; and (v) prognostic factors that determine the outcome (outcome can be complete relief, dissatisfaction, discomfort, disability, disease, or death). In a research setting, all or a subset of these may require assessment.
A “factor” in our terminology is a characteristic of the subjects, and the “indicator” is its measurement. Obesity is a factor and body mass index (BMI), waist–hip ratio (WHR), and skinfold thickness are its indicators. The indicator converts a factor into its operational definition. This distinction is important for proper implementation of research.
This chapter first discusses the intricacies of assessment of medical factors such as univariate and multivariate assessments, and the assessment in the implementation and the results phase of the study. The next section is on the type of medical factors and choice of indicators, and the last section provides details of the assessment of mortality, various durations, and quality of life that require special handling.
