Healthcare and Medicine Reference
Reasoning in Step-by-Step
Clinical Work and Care:
Risk, Diagnosis, Treatment,
In clinical practice and community medicine, and in public health as well,
we reason and make decisions in four particular domains: (1) assessing risk
(probability of new phenomena) in the individual patient and in the commu-
nity; (2) detection and diagnosis of disease and other phenomena in individ-
uals and their groups (sporadicity, epidemicity, endemicity, and pandemicity);
(3) choosing, implementing, and evaluating success and failures of clinical
treatment, prevention, and other active interventions; and (4) forecasting and
evaluating potential and real outcomes of health phenomena of interest.
In the assessment of risk, risk factors (events that may be modified) are
often of greater interest for pragmatic reasons than risk markers as uncon-
trollable predictors of disease and its cure. Results may be seen as significant
not only from a biostatistical or epidemiological point of view but also from
values attributed to them by patients and their communities. Post hoc ergo
propter hoc or cum hoc ergo propter hoc and other fallacies in causal reason-
ing should be avoided.
Diagnosis is made by various reasoning methods such as pattern recogni-
tion, hypothetico-deductive, probability-based, or deterministic approaches.