Health Psychology: Chapter 2

  - Confirmation bias: tendency to only focus on evidence that confirms what we already believe. - One of multiple unscientific thinking patterns that can explain why two people look at same data and draw different conclusions - In 1914 Goldberger designed and implemented tw...

  - Confirmation bias: tendency to only focus on evidence that confirms what we already believe. - One of multiple unscientific thinking patterns that can explain why two people look at same data and draw different conclusions - In 1914 Goldberger designed and implemented two experiments to assess whether improving the diet of institutionalized children and adults would prevent pellagra. - The study violates ethical standards that all scientists today. Today colleges, universities, and most medical institutions have an Institutional Review Board (IRB) that protects research participants from harm by permitting only studies that follow a strict code of ethics---a sort of moral code that provides researchers with guidelines about where to draw the line between what is "right" and what is "wrong."     **Critical Thinking and Evidence-Based Medicine:**   - Health psychology touches on some of the most intriguing, personal, and practical issues of life. - To make good decisions, health psychologists, students, physicians---indeed, every one of us---need a "lens" through which to examine the information we are bombarded with. - Evidence-based medicine: an approach to health care intended to optimize decision making in treating patients by integrating the best research evidence with clinical expertise and patient values. - Means that all medical interventions are subjected to testing and evaluation of efficacy before adopted as a standard of care. - At the heart of evidence-based medicine is an attitude that encourages health care providers to evaluate evidence and inspect conclusions. - Critical thinking: involves a questioning approach to ALL information and arguments.   **The Dangers of Unscientific Thinking:** - To understand healthy behaviour, we draw on available info to form cause-and-effect-relationships about behaviours. - It is dangerous to base explanations on unverified sources, hearsay, personal accounts, etc. - Health misinformation thrives online, especially during a crisis such as the COVID-19 pandemic. Such misinformation has the potential to cause harm. An unproven or useless treatment may have dangerous side effects or prevent the use of an effective, evidence-based intervention (for example, taking an over-the-counter vitamin supplement to prevent viral infection while abstaining from mask use and social distancing). The spread of COVID misinformation also fueled hostility, racism, and discrimination toward groups believed to be responsible for the pandemic     **Health Psychology Research Methods:** - Health psychologists use various research methods in their search to learn how psychological factors affect health. The method used depends in large measure on what questions the researcher is seeking to answer. - There are two major categories of research methods in psychology: descriptive and experimental. - Health psychologists also borrow methods from epidemiology. - Epidemiology: seeks to determine frequency, distribution, and causes of a particular disease or other health outcome in a population. A table of data analysis Description automatically generated   **Descriptive Studies:** - Researchers look for answers about behaviour of an individual or a group of people as it occurs in the home, at work, or wherever people spend their time. - In a descriptive study, the researcher observes and records the participants\' behaviour in a natural setting, often forming hunches that are later subjected to more systematic study. - Descriptive studies cannot tell us about the causes of observed behaviours. - Types of descriptive studies: - Case studies, interviews, surveys, focus groups, and observational studies. - Case study: a study where one person or group is studied in depth in hope of revealing general principles. - Advantage - useful in suggesting hypotheses for further study. - Disadvantage - may be not representative of others in population, limiting the result\'s generalizability. - Interviews are often used by clinical health psychologists as a start to developing relationships with patients. They also use surveys as a diagnostic assessment to develop intervention programs. - Focus groups (small number of patients gather to discuss topic) are sometimes used as an alternative to interviews. - Disadvantage - different wording can change the response you get without meaning to in surveys. Another limitation is that respondents may answer the way they think they should (not genuine). - **Observational Studies:** - Observational studies: the researcher observes participants\' behaviour and records relevant data. - Ex. a researcher interested in the physiological effects of everyday hassles might have participants wear a heart-rate monitor while commuting to and from school or work in rush-hour traffic. - Observational studies can be structured or unstructured. - Structured observations take place in the lab and involve role-playing or responding to certain stimulus. - Unstructured observations/naturalistic observation involves observing without intruding, recording participant\'s behaviour. - **Correlation:** - Descriptive studies often reveal info about 2 variables that may be related. To determine extent of suspected relationship, psychologists calculate correlation coefficient. - Correlational coefficient: measure of the strength and direction of relationship between 2 variables. - A scatterplot can be used to show the correlation of the variables - Even when 2 variables appear strongly correlated, one does not necessarily cause the other, there could be a third factor. - Correlations don't rule out possible contributions of other variables. When 2 variables are casually related, correlations do not indicate directionality.   **Experimental Studies:** - Experiments are used to test casual relationships. - Unlike descriptive studies, experiments test hypotheses by manipulating 1 or more independent variables (causes) while looking for changes in dependent variables (effects) and controlling all other variables. - By controlling all variables except independent variable, the researcher ensures that any change in the dependent variable is actually caused by the independent variable, rather than by another extraneous variable. - Typically, a random sample of participants is assigned to 2 or more study groups and administers the treatment of interest (independent variable) to one group (experimental group), and a different/no treatment to the other (control group).   **Quasi-Experiments:** - Quasi-experiment: a study comparing 2 groups that differ naturally on a specific variable of interest. - Not a true experiment because it uses groups that differ from the outset on the variable under study (the subject variable). - No cause-an-effect conclusions can be drawn. - Ex. suppose that researchers wish to investigate the effect of exercise on academic achievement. In a quasi-experiment, the subject variable would be a sedentary lifestyle, with the group consisting of students who by their own admission get little or no exercise. The comparison group would be students who exercise regularly. Health psychologists would collect data on the participants' base levels of daily physical activity over a defined period of time and then identify separate "active" and "sedentary" groups. The researchers would follow these comparison groups for a period of years, regularly reassessing the groups' activity levels and academic achievement. - Subject variables commonly used in quasi-experiments include age, gender, ethnicity, and socioeconomic status - all variables that are either impossible or unethical to manipulate.   **Developmental Studies:** - To answer questions about the process of change, researchers use 2 basic techniques: - **Cross-Sectional Study:** - Cross-sectional study: data is collected from a population, or representative subset, at one specific point in time. - Limitations of this technique include: - Need to make sure that the various groups are similar in ways other than different levels of the independent variable (such as economic status) that might affect characteristic being investigated. - If the groups are similar, then any differences in early patterns among them may be attributed to variable of interest. - They don't reveal info about changes in people over a period of time. - **Longitudinal Study:** - Longitudinal study: a single group of individuals is observed over a long span of time. - This technique allows for info about a person at one age to be compared to info about that person at a different age, revealing how they've changed over time. - Some drawbacks include: - Very expensive and time consuming - Common for participants to drop out (pass away, move away, etc.) because of length of the study, skewing results. - Participants may change in the characteristic of interest     **Epidemiological Research - Tracking Disease:**   - Who contracts which diseases, what factors determine whether a person gets a disease? - These are questions that are addressed by field of epidemiology. - Epidemiology: seeks to determine frequency, distribution, and causes of a particular disease or other health outcome in a population. - In 184, John Snow analyzed the distribution of cholera cases in London during an epidemic. Snow concluded that access to uncontaminated water prevented them from cholera infection, while users of the Broad Street pump became infected. - Since then, epidemiologists have described in detail the distribution of many different infectious diseases. They have identified many risk factors linked to favourable and unfavourable health outcomes. - In a typical study, epidemiologists measure the occurrence of a particular health outcome in a population and attempt to discover why it is distributed as it is by relating it to specific characteristics of people and the environments in which they live. - In epidemiology, a disease vector is any agent which carries and transmits an infectious pathogen into another living organism. - Ex. COVID-19 - Epidemiologists record morbidity and mortality - Morbidity: number of cases of a specific illness, injury, or disability in a given group of people at a given time. - Mortality: number of deaths due to a specific cause (such as heart disease), in a given group at a given time. - Morbidity and mortality are outcome measures that are usually reported in terms of incidence and prevalence. - Incidence: the number of new cases of a disease, infection, or disability, such as whooping cough, that occur in a specific population within a defined period of time. - If epidemiologists wish to know the frequency with which hypertension is diagnosed, they would look at incidence rates. - Prevalence: total number of diagnosed cases of a disease or condition that exist at a given time. - Includes both previously reported cases and new disease or condition that exist at a given time. - The prevalence of a chronic disorder such as hypertension is much greater than the incidence because people can live for many years following diagnosis. - If epidemiologists wish to know how many people overall have hypertension, they would examine prevalence rates.   **Objectives in Epidemiological Research:** - Epidemiologists use several research methods to obtain data on the incidence, prevalence, and etiology (origins) of disease. - Epidemiologists have 3 fundamental objectives: 1. Identify etiology of particular disease in order to generate hypotheses. - Starts by counting current cases of illness (prevalence) or the rate at which new cases appear (incidence) in order to describe overall health or population. - Then analyze info to generate hypotheses about which subgroup differences are responsible for the disease. 2. Evaluate hypotheses. - Once the origins of a disease/condition have been identified as well as a generated hypotheses about its causes, they evaluate those hypotheses. - Ex. Some doctors have noted that lung cancer is more likely to develop in women who smoke vs. men that smoke. Could this be due to hormonal differences or some other sex-related factor? 3. Test hypotheses by assessing effectiveness of specific preventive health interventions. - They test new hypotheses by attempting to predict the incidence and prevalence of diseases. If the predictions are borne out by epidemiological data, researchers gain confidence that their etiology (origins) of the disease is increasing. - The final goal is to assess effectiveness of intervention programs created to test the researchers\' hypotheses.   **Research Methods in Epidemiology:** - To achieve their purposes, epidemiologists use a variety of research methods: retrospective studies, prospective studies, and clinical trials - **Retrospective Studies:** - Retrospective studies: longitudinal study that looks at history of a group of people, often one suffering from particular disease or condition. - Ex. This type of research played an important role in identifying risk factors that led to AIDS. Epidemiologists were able to pinpoint unprotected anal sex as a common background factor among the first men to die from this. - Ex. INTERHEAT - study of risk factors for. Acute myocardial infraction (heart attack). Comparison group was made (shared same characteristics apart from the disease). This was a case-control study. - Case-control studies: retrospective study where people with a disease or condition (cases) are compared with people who aren\'t affect by the disease/condition (controls). - **Prospective Study:** - Prospective study: longitudinal study that begins with a healthy group of subjects and follows the development of a particular disease in that sample. - This method can yield more specific info than retrospective studies about potential casual relationships between health behaviours (or risk factors) and health outcomes. - Ex. Hostility in men and cardiovascular disease. A prospective study would have researchers follow hostile men with healthy hearts over time to see whether they would eventually develop cardiovascular disease at higher rates than nonhostile men. - **Clinical Trials:** - Randomized clinical trial (RCT): tests effects of one independent variable (such as particular drug/treatment) on individuals or on groups of individuals (community field trials). - The most common clinical trial for individuals involves measurement of a baseline (starting point) level of a condition, followed by a measure of the effectiveness of a treatment. - In the most common type of clinical trial involving groups, baseline measures are taken, and participants are then randomly assigned to either an experimental group that receives the treatment of interest, such as a new headache med, or a control group that receives placebo (harmless pill). - If outside variables have been controlled properly, then differences in the group can be attributed to differences in the treatment. - **Meta-Analysis:** - Meta-analysis: quantitative technique that combines results of studies examining the same effect or phenomenon. - Just as an experiment examines the consistency in the responses of individual participants, a meta-analysis determines the overall consistency of individual studies that address the same topics. - A meta-analysis does not replace individual studies; rather, it provides a systematic procedure for summarizing existing evidence about focused research hypotheses that already appear in the health psychology literature. - Advantages: - By pooling results of many studies, meta-analysis often reveals significant results simply because combined studies have more participants. - Demonstrating that a finding holds up across different studies conducted by different researchers at different times and places and with different participants gives researchers greater confidence in the finding\'s validity. - As with good experiments, meta-analysis is subject to replication. That ism other researchers may repeat the series of statistical steps and should reach the same conclusions.   **Inferring Causality:** - Regardless of which method epidemiologists use, certain base conditions must be met before a cause-and-effect relationship can be inferred between a particular risk factor and particular disease or other adverse health outcome: - Evidence must be consistent. - Studies that report an association between a risk factor and a health outcome must be replicated. - Alleged cause must have been in place before the disease actually appeared. - The relationship must make sense. - Explanation must be consistent with known physiological findings. - There must be a does-response relationship between the risk factor and health outcome. - Dose-response relationship: systematic associations between a particular independent variable, such as cigarette smoking, and a particular dependent variable, such as breast cancer. - The strength of the association between the alleged cause and the health outcome (relative risk) must suggest causality. - Relative risk: the ratio of the incidence or prevalence of that condition in a group not exposed to risk factor. - The incidence or prevalence of the disease or other adverse health outcome must drop. When the alleged causal factor is removed. - When all conditions are met, epidemiologists are able to infer that causal relationship has been established, even when a true experiment cannot be conducted.   **Research Ethics and Scientific Misconduct:** - APA and NSF have research guidelines that protect the well-being of research participants. Must be completely voluntary, researchers must: - Obtain participants informed consent beforehand - Protect participants from harm and discomfort - Keep information about individual participants confidential - Fully debrief people (explain research afterward) - Scientific misconduct: violation of accepted codes of scholarship and ethical behaviour in research. - NSF defines 3 types of misconduct: - Fabrication: the act of inventing false information in order to deceive someone, or the false information itself. - Falsification: the act of deliberately lying about or misrepresenting something. - Fabrication is making up data or results, while falsification is manipulating data or results. - Plagiarism: taking someone else\'s work or ideas and passing them off as one\'s own.   **Summing Up:** Critical Thinking and Evidence-Based Medicine - Our everyday thinking is prone to bias, including making snap judgments and inferring cause and effect inappropriately. Using scientific research methods to search for evidence will help you become a more careful consumer of health psychology reports.   Health Psychology Research Methods - Descriptive studies, which observe and record the behavior of participants, include case studies, interviews and surveys, focus groups, and observation. - The strength and direction of a relationship between two sets of scores are revealed visually by scatterplots and statistically by the correlation coefficient. Correlation does not imply causality. - In an experiment, a researcher manipulates one or more independent variables while looking for changes in one or more dependent variables. Experiments typically compare an experimental group with a control group. - When health psychologists study variables that cannot be manipulated, they may conduct a quasi-experiment in which participants are assigned to comparison groups on the basis of age, gender, ethnicity, or some other subject variable. - Developmental studies focus on the ways people change or remain the same over time. In a cross-sectional study, data are collected on the whole study population (such as comparing groups of people of various ages) at a single point in time. - In a longitudinal study, subjects are followed over a long span of time. To compensate for the problem of subjects dropping out over a lengthy span of years, researchers have developed a cross-sectional study, in which different age groups are tested initially and then retested later at various ages.   Epidemiological Research: Tracking Disease - Epidemiological research studies measure the distribution of health outcomes, seek to discover the etiology of those outcomes, and test the effectiveness of health interventions. Among the commonly used epidemiological statistics are morbidity, mortality, incidence, and prevalence. - Epidemiologists use several basic research designs, including retrospective and prospective studies. - Epidemiologists use several measures of risk: absolute risk, relative risk, and attributable risk. - Meta-analysis analyzes data from already published studies, statistically combining the size of the difference between the experimental and control groups to enable researchers to evaluate the consistency of findings. - In order to infer causality in epidemiological research, research evidence must be consistent and logically sensible and exhibit a dose--response relationship. In addition, the alleged cause must have been in place before the health outcome in question was observed and must result in a reduced prevalence of the condition when removed. - Ethical research entails ensuring certain protections for participants, and avoiding fabrication, falsification, plagiarism, and inequities in which populations are most often studied.   **Key Terms and Concepts:** - confirmation bias - evidence-based medicine - critical thinking - Epidemiology - descriptive study - observational studies - correlation coefficient - Scatterplot - quasi-experiment - cross-sectional study - longitudinal study - Vector - Morbidity - Mortality - Incidence - Prevalence - Etiology - retrospective studies - case--control studies - prospective study - randomized clinical trial - meta-analysis - relative risk - attributable risk - qualitative research - informed consent - debrief