Unreliable item or inconsistent person? A study of variation in health beliefs and belief-anchors to biomedical models

Abstract

Several models for health beliefs grounded in social theories have been extensively used in health-related research. However, the measurement of beliefs, especially the stability of beliefs, is still an understudied area. For example, reliability of an item designed to measure health belief is often confounded with response consistency at the person level, and the problem is often ignored in social research in medicine. To delineate discordant responses to the same item of belief in diabetes, which could be due to item unreliability or to respondent inconsistency, we applied contemporary measurement methods to an inventory of common sense beliefs about diabetes and tested the hypothesis that individuals whose health beliefs are congruent with a biomedical model are more consistent in their item responses. Approximately equal numbers of Whites, African Americans, and American Indians (total N=563) with diabetes were recruited into the study from rural areas in North Carolina. The Common Sense Model of Diabetes Inventory, which contained 31 items across six clinical domains, was administered to the participants at baseline and then one month later. Concordance between responses was analyzed using item response theory. Item-level analysis revealed that items in the domains of Causes of Diabetes and Medical Management of Diabetes were less reliable compared to items from other domains. Person-level analysis showed that respondents who held views congruent with the biomedical model were more consistent than people who did not. Item response theory facilitates a process to evaluate item unreliability and differences in distinguishing response consistency. People with diabetes who had beliefs regarding diabetes not congruent with the biomedical model tended to be less stable in their beliefs and should be more amenable to diabetes education and other interventions.

Analysis of Multiple Partially Ordered Responses to Belief Items with Don’t Know Option

“…As part of a study of health beliefs and behavior on adults with diabetes who live in rural areas in the U.S. (Arcury et al, 2012; Quandt et al, 2012), the data used in this analysis were collected from the instrument CSMDI, which measures common-sense beliefs about their disease held by individuals with diabetes (Ip et al, 2013c). The CSMDI is composed of a battery of 31 items, which cover beliefs in six different domains—symptoms, causes, consequences, information, behavioral management of diabetes, and medical management of diabetes.…”

“…The reason we used information from both study visits is that the common sense beliefs expressed by the participants could vary substantially across different measuring occasions. The response inconsistency observed in this kind of data is sometimes above and beyond measurement error and reflects a person’s level of ambivalence about a specific belief (Ip et al, 2013c). The poset in Fig.…”

“…They found that lay beliefs about diabetes were not always stable across specific domains of diabetes such as causes of the disease and its medical management, as well as across different ethnic groups. Using item response theory (IRT), Ip et al (2013c) examined the consistency of item responses on belief items about diabetes from an instrument – the Common Sense Model of Diabetes Inventory (CSMDI, Grzywacz et al, 2011) over two different occasions of measurements. An example of an item is “Feeling nervous is a sign of low blood sugar.” The items have three response categories: “Agree,” “Disagree,” and “Don’t Know (DK).” Each response was judged as congruent or incongruent to the biomedical model.…”

Can the Pain Attitudes and Beliefs Scales be adapted for use in the context of osteoarthritis with general practitioners and physiotherapists?

“…This issue may be compounded by inconsistent interpretation of the behavioural items. Ip et al [44] indicated that such problems could relate to differences in the belief anchors that link a belief to either the biomedical or biopsychosocial belief systems. Those authors explored health and illness beliefs among people with diabetes and found that biomedically-located anchors were reported more consistently than other anchors [44].…”

Exploring the utility of the Pain Attitudes and Beliefs Scale with general practitioners and physiotherapists in the context of osteoarthritis: a cross-sectional observational study

“…This issue may be compounded by inconsistent interpretation of the behavioural items. Ip et al (52) indicated that such problems could relate to differences in the belief anchors that link a belief to either the biomedical or biopsychosocial belief systems. Those authors explored health and illness beliefs among people with diabetes and found that biomedically-located anchors were reported more consistently than other anchors (52).…”