In the 1950s, pulmonary tuberculosis became rampant in some neighborhoods in the US. To catch the bacteria as early as possible, the US health authorities had been X-raying people’s chest to detect lung changes that are caused by this micro beast.
However, there was a problem; even though the service was free of charge, not all people attended those clinics. They wanted to find out why.
Geoffrey Hochbaum and his team designed a multi-site research project to find answers to the following questions.
- What factors influenced community members in deciding either to attend or not to attend the clinic?
- What factors influenced them to obtain the service after deciding to attend the service?
How did they conduct the study?
They interviewed random samples from 3 cities totaling to 1,200 individuals; 450 in Boston, 450 in Cleveland, and 300 in Detroit. They adopted a random sampling approach because they wanted to generalize their findings to study populations. Each interview lasted more than an hour and covered themes related to participants’ beliefs, attitudes, and feelings regarding the activity including services’ administrative aspects.
In addition to traditional question items with close and open-ended questions, they included projective questions that lead participants to awaken their subconscious level of thinking.
What did they find?
- 42% attended the service voluntarily without any symptoms.
- Another 16% attended due to their suspicion of having symptoms,
- Another 14% attended due to their significant others’ influence.
- Another 10% who attended did not show any consistent pattern.
- 17% did not attend.
Perhaps, the most crucial finding was that only 35% of those who knew that tuberculosis can exist without having symptoms obtained a chest X-ray. This signifies that there were some other factors that influenced their decision making for attending the service apart from awareness. This holds true even today – not all who are aware of the usefulness of screening programs such as mammography and colonoscopy, do not attend those services.
However, moving beyond the above findings, Godfrey Hochbaum in the article named, ” Why people seek diagnostic X rays?” published in the Public Health Reports in 1956 demonstrated how the participants’ beliefs/perceptions interfered in translating awareness into actions. I am highlighting here two important beliefs/perceptions: susceptibility and usefulness.
Group 1: Those who perceived that they were susceptible.
Of those who believed that they would contract the disease (perceived susceptibility), 82% attended the service. In contrast, of those who did not believe so, fewer than 50% attended the service.
Group II: Those who perceived that a X-ray would help having better outcomes.
Of those who believed that having an X-ray without symptoms would help to have better outcomes, 90% attended the service.
In this study, the researchers wanted to find out why those with a higher risk of contracting the disease did not attend the service – individuals with lower socio-economic backgrounds and older people. They found that the above findings held true regardless of study participants’ socio-economic status, age, and gender.
As pointed out by Rosenstock, the major methodological limitation is the study’s retrospective nature in that both existing beliefs and behavior (having an X-ray) were inquired at the same time. This is because people tend to change their previous perceptions in accordance with their later decisions as shown by Festinger’s cognitive dissonance theory.
In contrast to the Godfrey Hochbaum’s retrospective study, Kegeles conducted a two-phase prospective study with individuals who had a pre-paid dental care plan and their subsequent preventive health visits: first, he inquired about their beliefs and second, three years later, about their visits to a dental clinic. Then he compared these findings with a control group from the same company. Both groups were stratified by age and marital status for analyses.
Following were his findings:
- 58.2% who felt susceptible made dental visits whereas 41.9% who did not feel susceptible made dental visits. This finding was statistically significant, p* (X2 = 5.18) < .05.
- 47.5% who perceived benefits of dental visits, made dental visits whereas 44.6% who did not perceive benefits of dental visits made dental visits. However, this finding was not statistically significant.
- 67.3% who felt susceptible and perceived benefits if such visits made dental visits whereas only 38.1% of those who did not feel susceptible and perceive the benefits of such visits made dental visits. This finding was statistically significant, p (X2 [Yates]t = 5.42) < .01.(page 169).
Questions they used.
The question they used to assess perceived susceptibility was, “how likely do you think that your worst dental problem or such a problem will happen to you again? The responses were likely and unlikely.
However, it is important to note here that they had used open-ended questions during the first phase and close-ended questions during the second phase.
As summarised by Rosenstock, Kegeles found when both perceived susceptibility and perceived benefits exist together, more participants took action than those beliefs considered separately.
An important critique by Rosenstock
Rosenstock pointed out two important factors that needed to be addressed at that time: cues to action and perceived access to the services. However, He did not cite specific studies to support his claim. Instead, he referenced the following model presented by Becker (1974) tested in his study. I will discuss his methodology in a later post.
Graphical presentation of the Health Belief Model (Becker, 1974)