Two Key Studies of the Biopsychosocial Model (DP IB Psychology)

Key study one: Marmot et al. (1997)

Aim: 

• To find out whether employees in lower position jobs - that is, with less control over their work environment - would develop heart problems over five years

Participants: 

• 7000 male and female civil servants aged between 35 and 55 years old and working in Whitehall, London 

Procedure: 

• This was part of an ongoing prospective longitudinal study 

• The participants were invited to the research clinic where medical checks were carried out

• A standardised self-report questionnaire was sent to their homes at yearly intervals for the next five years

• The questionnaires gathered demographic information, information about health, and job status and about the amount of control participants had at work

• Social measures were used, such as self-reported environmental stressors like:

  • neighbourhood problems

  • housing

  • loneliness

  • social support

• Self-reported heart problems and cases of diabetes or cancer were verified by hospital records

• Job specifications and responsibilities were also measured through independent assessments of the work environment by personnel managers

Results:

• The rate of heart problems for those in the lowest levels of the civil service system was 1.5 times the rate in the highest levels

• Risk factors such as smoking, obesity, and high blood pressure could account for some of the differences

• The most significant risk factor for developing heart disease was the degree of control that participants felt they had in the work environment

Conclusion:

• There is a correlation between low control over one’s work and heart disease

• Therefore those with low control over their day-to-day working life were more likely to develop heart disease

Civil servants with the lowest job status had the worst health

Evaluation of Marmot et al. (1997)

Strengths

• The use of standardised questionnaires, objective health measures and correlational analysis means that the study has some degree of reliability

• The longitudinal design of the research means that the data from this study can be compared with data from previous and future research

Limitations

• There are common problems with self-report questionnaires:

  • Social desirability effect - participants may underestimate their own health problems

  • Different interpretation of the question from that intended

  • Forced choices in closed-ended questions may not have matched participants’ preferred answer

  • Fear that confidentiality may not be maintained may lead to untruthful answers or some questions not being answered 

• A correlation can only suggest association rather than cause-and-effect so it cannot conclusively show what the source of the stress was in each participant’s life

Key study two: Suls and Rothman (2004)

Aim: 

• To assess the extent to which health psychologists use the multiple systems (biological, psychological, sociocultural) that underlie the biopsychosocial model

Procedure: 

• Meta-analysis - researchers independently read and coded for key words all of the studies (numbering seventy) published in Health Psychology journal between November 2001 and September 2002

• They documented how many times biological variables, psychological variables, social variables, and macro variables were being assessed in the seventy studies 

• Social variables focused on factors like self-reported social support and marital satisfaction, while macro variables were considered sufficient only if the studies had measured at least age, gender, ethnicity, and either education or income.

Results:

• Only 26% of the studies included measures from all four domains (i.e., biological, psychological, social, and macro)

• 38% included measures in three of the four domains

• Psychological variables were measured in over 94% of the studies being assessed, but biological, social and macro variables only showed up in around half of the studies

• The inclusion of biological and social factors was limited, in terms of reference to the actual aim of the study undertaken by the health psychologist:

  • Biological factors assessed mainly referred to a disease used to determine the sample

  • Social factors assessed measured people’s subjective judgments about relationships with friends and family

  • Macro variables assessed were simply used to describe the demographics of the sample

• Studies reviewed mainly focused on the interactions between either psychological and social factors or psychological and biological factors

Conclusion:

• While health psychologists have acknowledged the biopsychosocial model enough to reference it in their research, their studies are not focused on the links between the different domains

• Research exploring interconnections between biological and social factors appear to have been especially limited

Evaluation of Suls and Rothman (2004)

Strengths

• The information is objective and complete, covering an 11-month period and using two coders who agreed on the word categories, leaving little room for researcher bias

• The meta-analysis is thorough and investigates to what extent each of the biological, psychological, and social components are conceptually linked rather than regarded as separate entities are merely used to help sample selection

Limitations

• The words were coded without much context and so we have little understanding about how the variables associated with the biopsychosocial model were weighted or analysed

• The study was carried out between 2001 and 2002, so it is over twenty years old and the findings therefore lack some temporal validity, as the frequency of use of the biopsychosocial model by medical practitioners may well have increased