In addition, if doctors’ behaviour were objective then their behaviour would be consist-
ent. However, considerable variability among doctors in terms of different aspects of
their practice has been found. For example, Anderson et al. (1983) reported that doctors
differ in their diagnosis of asthma. Mapes (1980) suggested that they vary in terms of
their prescribing behaviour, with a variation of 15–90 per cent of patients receiving
drugs. Bucknall et al. (1986) reported variation in the methods used by doctors to
measure blood pressure and Marteau and Baum (1984) also reported that doctors vary
in their treatment of diabetes.
According to a traditional educational model of doctor–patient communication, this
variability could be understood in terms of differing levels of knowledge and expertise.
However, this variability can also be understood by examining the other factors involved
in the clinical decision-making process.Explaining variability – clinical decision making as problem solving
A model of problem solving
Clinical decision-making processes are a specialized form of problem solving and have
been studied within the context of problem solving and theories of information pro-
cessing. It is often assumed that clinical decisions are made by the process of inductive
reasoning, which involves collecting evidence and data and using this data to develop a
conclusion and a hypothesis. For example, within this framework, a general practitioner
would start a consultation with a patient without any prior model of their problem.
The GP would then ask the appropriate questions regarding the patient’s history
and symptoms and develop a hypothesis about the presenting problem. However,
doctors’ decision-making processes are generally considered within the framework of
the hypothetico-deductive model of decision making. This perspective emphasizes the
development of hypotheses early on in the consultation and is illustrated by Newell and
Simon’s (1972) model of problem solving, which emphasizes hypothesis testing. Newell
and Simon suggested that problem solving involves a number of stages that result
in a solution to any given problem. This model has been applied to many different
forms of problem solving and is a useful framework for examining clinical decisions (see
Figure 4.2).
The stages involved are as follows:1 Understand the nature of the problem and develop an internal representation.
At this stage, the individual needs to formulate an internal representation of the
problem. This process involves understanding the goal of the problem, evaluating any
given conditions and assessing the nature of the available data.
2 Develop a plan of action for solving the problem. Newell and Simon differentiated
between two types of plans: heuristics and algorithms. An algorithm is a set of rules
that will provide a correct solution if applied correctly (e.g. addition, multiplication,
etc. involve algorithms). However, most human problem solving involves heuristics,
which are rules of thumb. Heuristics are less definite and specific but provide86 HEALTH PSYCHOLOGY