Source: Health Psychology, 11th Edition by Taylor, Chapter 1
Difficulty: Introductory | Prerequisites: Read Part 1 (Introduction to Health Psychology) first for the foundational models.
This second half of the Chapter 1 material covers the practical mechanics of health psychology: why the field emerged (the shift from acute to chronic illness), how researchers study health behaviours (experiments, correlational designs, prospective and retrospective methods), and the epidemiological concepts used to track disease. These research methods come back in every subsequent chapter, so learning them now saves you repeated confusion later.
Chronic illnesses replaced acute infections as the leading killers, creating a need for behavioural and psychological approaches to health. Health psychologists use experiments, randomised clinical trials, correlational studies, prospective and retrospective designs, and meta-analyses. Epidemiology provides the population-level data (morbidity, mortality, incidence, prevalence) that frames the field's research questions.
Until the 20th century, the major killers in the United States were acute disorders: tuberculosis, pneumonia, and other infectious diseases. These are short-term illnesses that are usually amenable to cure.
Treatment innovations and improvements in public health standards drove acute infectious diseases into decline. The leading causes of disability and death in industrialised countries are now chronic illnesses, such as heart disease, cancer, and respiratory diseases.
Chronic illnesses differ from acute ones in important ways:
They develop slowly and persist for years
They are not curable, only manageable
Social factors are implicated as causes
They affect relationships with partners and family
They require the patient and practitioner to co-manage care over the long term
This epidemiological shift is the single most important reason health psychology exists. When the main killers were bacteria and viruses, a purely biomedical approach worked reasonably well. When the main killers are lifestyle-related chronic conditions, psychological and behavioural factors become central.
According to the U.S. Census Bureau, in 2010, approximately 49.9 million Americans had no health insurance. Despite substantial increases in healthcare spending, improvements in basic health indicators have not kept pace. The healthcare industry is not closely monitored and well-managed in this respect (a common exam trap: the statement that rising costs have led to tremendous health improvements is false).
Health psychologists contribute to this space by understanding what makes people satisfied or dissatisfied with their care, and by emphasising prevention to reduce the dollars devoted to managing illness after it develops.
Behavioural interventions targeting risk factors such as diet and smoking have contributed to the decline in the incidence of coronary heart disease in particular. This is a concrete example of health psychology in action.
Most research in health psychology is guided by practical problems (not proven theory, government agencies, or clinical trials). Much of the research is experimental in nature.
A theory is a set of analytic statements that explain a set of phenomena, such as why people practise poor health behaviours. Good theories generate specific (not nonspecific) predictions, provide guidelines for research and interventions, are testable, and the best ones are simple and useful.
In an experiment, a researcher creates two or more conditions that differ from each other in exact and predetermined ways. Experiments remain the mainstay of science because they typically provide more definitive answers than other methods. (Exam trap: the statement that experiments have "ceased to remain the mainstay" is false.)
When a patient is informed about a procedure, its difficulties, and pain management techniques (as in the textbook's Janelle scenario), they are most likely to improve their adjustment toward the procedure.
An RCT is an experiment conducted by a healthcare practitioner to evaluate treatments or interventions and their effectiveness over time. Key features:
A target treatment is compared against an inert (control) treatment
Participants are randomly assigned to conditions
This is the gold standard for evaluating whether interventions work
Evidence-based medicine is medical intervention that has gone through rigorous testing via RCTs.
Correlational research measures whether a change in one variable corresponds with changes in another. For example, studying the relationship between feelings of social connection and healthcare visits.
Advantage: useful when variables cannot be manipulated experimentally.
Major disadvantage: the direction of causation is unclear. (Correlational studies are not "less adaptable" than experiments; that framing is false.)
Prospective research looks forward in time to see how a group of people change, or how a relationship between two variables changes over time. Using a prospective design can remedy some of the problems with correlational research.
Two sub-types:
Experimental prospective – the researcher intervenes in one group but not another and tracks the outcome over time (e.g. changing one community's diet and comparing heart disease rates)
Correlational prospective – the researcher measures variables people create for themselves (e.g. self-selected diets) and tracks outcomes over time
Longitudinal research is a particular type of prospective study in which the same people are observed at multiple points in time.
Retrospective research looks backward in time, attempting to reconstruct the conditions that led to a current situation. Retrospective methods were critical in identifying risk factors for the development of AIDS.
Both prospective and retrospective methods help remedy the problems of correlational research by adding a time dimension.
Meta-analysis combines results from different studies to identify how strong the evidence is for a particular research finding. It is a powerful methodological tool because it uses a broad array of diverse evidence to reach conclusions.
Guided interviews and narratives can provide insights into health processes that summary statistics may not. For example, interviews with cancer patients about their chemotherapy experiences may be more helpful in redesigning treatment delivery than numerical satisfaction ratings. Quantitative and qualitative methods work hand in hand to develop research evidence for effective interventions.
Epidemiology is the study of the frequency, distribution, and causes of infectious and non-infectious diseases in a population. Epidemiologists study who has what kind of disease and also address why certain diseases are more prevalent in particular geographic areas.
Key measures:
Morbidity – the number of cases of a disease at a given point in time. It can be expressed two ways: as incidence (new cases) or as prevalence (total existing cases).
Mortality – the number of deaths due to a particular cause.
Incidence – new cases only.
Prevalence – all existing cases (new plus ongoing).
Functional magnetic resonance imaging (fMRI) – a scientific tool that permits glimpses into the brain. Used in health psychology to study neural correlates of pain, stress, and health behaviours.
Ambulatory monitoring devices – made available to people with hypertension so they can successfully monitor their blood pressure in daily life.
Ecological momentary interventions – use mobile technologies (phones, tablets, pagers) to deliver interventions and assess health-related events in the person's natural environment.
The primary concern for health psychologists is health-related quality of life (not medication development, follow-up care access, or mortality rates per se).
Key allied professionals:
Social worker – assesses where patients go once discharged from a medical setting, based on psychosocial needs
Physical therapist – supports patients in regaining the use of bodily functions compromised by illness
Dietician – conducts dietary interventions for chronic illness patients
The APA formed the Division of Health Psychology in 1978, marking the field's formal institutional recognition.
Students confuse prospective (looking forward) with retrospective (looking backward). Prospective = future; retrospective = past. A mnemonic: "pro" = forward, "retro" = back.
Students think correlational studies are "less adaptable" than experiments. The real disadvantage is that causation direction is unclear, not adaptability.
Students assume meta-analysis is just "a big study." It is a method of combining existing studies, not running a new one.
Students mix up experimental prospective (researcher intervenes) with correlational prospective (researcher observes naturally occurring variables over time). The key distinction is whether the researcher manipulates a variable.
⚠️ Know the hierarchy of evidence: RCTs sit at the top, correlational studies below. Meta-analyses synthesise across studies.
⚠️ The 49.9 million uninsured Americans figure (2010) is a commonly tested statistic.
⚠️ The statement "experiments have ceased to be the mainstay of science" is false. Experiments remain the mainstay.
⚠️ Morbidity can be expressed as incidence (new cases) or prevalence (all cases). This distinction is a favourite exam item.
⚠️ Behavioural interventions have been most associated with declines in coronary heart disease specifically.
⚠️ The primary concern for health psychologists is health-related quality of life.
⚠️ Retrospective methods were critical in identifying risk factors for AIDS in particular.
True or False: Most research in health psychology is guided by proven theory. (False – it is guided by practical problems.)
Fill in the blank: A major disadvantage of correlational research is that the direction of __________ is unclear. (Causation.)
True or False: Morbidity may be expressed as incidence or prevalence. (True.)
Fill in the blank: __________ research looks backward in time to reconstruct conditions that led to a current situation. (Retrospective.)
True or False: The healthcare industry's rising costs have led to tremendous improvements in basic health indicators. (False.)
Q: A researcher randomly assigns stressed adults to eat dark chocolate or drink water daily for 4 weeks. What type of study is this?
A: A randomised clinical trial. Random assignment to conditions with a control group is the defining feature.
Q: Sam studies the relationship between feelings of social connection and visits to the campus health centre. What type of research is this?
A: Correlational research. Sam is measuring the association between two variables without manipulating either.
Q: What is the major disadvantage of correlational research?
A: The direction of causation is unclear. You cannot tell which variable is causing changes in the other.
Q: A researcher intervenes in the diet of one community but not another, then tracks heart disease rates over time. What type of study is this?
A: An experimental prospective study. The researcher both manipulates a variable (diet) and follows participants forward in time.
Q: What distinguishes longitudinal research from other prospective designs?
A: In longitudinal research, the same people are observed at multiple points in time (rather than comparing different groups at different times).
Q: Why is meta-analysis considered a powerful methodological tool?
A: Because it uses a broad array of diverse evidence from multiple studies to reach conclusions about how strong the evidence is for a particular finding.
Q: What are the two ways morbidity can be expressed?
A: As incidence (number of new cases) or as prevalence (total number of existing cases).
Q: What is the primary concern for health psychologists?
A: Health-related quality of life.
The research methods covered here are the toolkit for the entire course. RCTs return in chapters on stress management and pain interventions. Correlational and prospective designs are used throughout the chapters on health behaviours (smoking, diet, exercise). Epidemiological concepts (incidence, prevalence, mortality) frame the discussions of chronic illness in later chapters. The distinction between acute and chronic illness sets up the chapters on coping with chronic disease, patient-provider communication, and adherence to treatment.
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