Health-related information helps patients cope with illness by increasing knowledge, reducing feelings of uncertainty, and enhancing emotional and social adjustment [1
]. When seeking information, patients have a number of sources from which to choose, including health professionals like physicians [2
], pharmacists [3
], and nurses [2
], health-related websites [4
], patient information leaflets [4
], mass media sources such as newspapers, magazines, and television [2
], and family and friends [2
]. The opportunity to encounter conflicting information arises when health information is obtained from more than one source and may vary based on whether information is received passively (i.e. from two different physicians) or actively obtained by patients during information searches (i.e. Internet information contradicts physician recommendations).
A burgeoning, primarily qualitative, literature has begun to document the extent to and conditions under which chronic disease patients receive conflicting information. The results from these studies demonstrate that people living with chronic conditions, such as cancer [7
], cardiopulmonary disease [3
], rheumatic disease [11
], low back pain [12
] as well as mental illness [13
] receive conflicting information about their illness and its management. Furthermore, several studies have documented that patients receive conflicting information about their medications [11
], although no published research has focused specifically on patients with rare health conditions.
Preliminary evidence suggests that receipt of conflicting information may negatively influence patients' perceptions of care [16
], increase anxiety [13
], alter risk perceptions [17
], and complicate patients' ability to assess the reliability of information sources [12
]. Health behavior models like the Information-Motivation-Behavioral Skills (IMB) Model [18
] offer insight into the potential mechanisms through which conflicting information may affect adherence. Specifically, the IMB model posits that adherence information, or factual information about medication adherence, has a positive effect on both adherence self-efficacy and medication adherence, and that self-efficacy acts as a mediator of the relationship between information and adherence. The IMB model also posits that motivation (i.e. perceptions of social support and adherence outcome expectations) influence adherence directly and indirectly through increased self-efficacy. Four cross-sectional tests of the model lend support to the posited relationships [19
], although the effect of information appears to be mediated through increased self-efficacy as opposed to having a direct effect on medication adherence.
In order to build upon the limited understanding of how conflicting information affects medication adherence, we collected longitudinal survey data from a sample of chronically ill patients. The IMB model served as the organizing framework for our conceptual model (), in which we hypothesize that a greater amount of conflicting information will result in more medication non-adherence. Additionally, we believe that self-efficacy and outcome expectations will partially mediate the relationship between conflicting information and non-adherence. Specifically, we posit that patients who receive more conflicting information will have decreased self-efficacy and more negative outcome expectations for medications, which will result in more non-adherence. Moreover, we hypothesize that social support from patients' physicians will result in less medication non-adherence and that this effect will be partially mediated through increased self-efficacy and more positive outcome expectations for medications.
Predicted relationships among conflicting information, physician support, outcome expectations, adherence self-efficacy, and medication non-adherence