Perceived Diagnostic Status, Pain-Related Guilt and Their Association with Mood and Disability in Low Back Pain

In the majority of low back pain (LBP) patients a clear diagnosis cannot be established. This may relate to how patients perceive and manage their condition, and to the development of pain-related guilt. This thesis presents a series of studies investigating the relationship between perceived diagnostic status, pain-related guilt and mood and disability in LBP. In Study 1 semi-structured interviews were conducted with LBP patients to explore their understanding, feelings and behaviour in response to their diagnostic status. Several participants experienced a state of diagnostic uncertainty which was associated with their social, emotional and cognitive functioning, and with seeking further treatment. Pain-related guilt emerged as a major theme and was further examined in Study 2 and 3, in which a pain-related guilt scale was developed and validated. Three subscales were identified: social guilt, managing condition/pain guilt and verification of pain guilt, and each subscale was positively correlated with pain, mood and disability. Study 4 aimed to amalgamate the findings from the first three studies and test a theoretical model in which diagnostic uncertainty predicted pain-related guilt, which in turn predicted mood and disability in LBP. The model provided a reasonable-to-good fit with the data, but the alternative models in which reversed relationships between guilt, mood and diagnostic uncertainty were tested were slightly better. Finally, Study 5 examined cognitive mechanisms underlying the relationship between diagnostic uncertainty and mood and disability; to this end an experimental study was conducted in which two groups of LBP patients were compared (certain vs. uncertain about diagnosis) on their selective recall of negative health stimuli. Only the group with diagnostic uncertainty displayed a recall bias towards negative health stimuli. Overall, the findings from this thesis suggest that diagnostic uncertainty and pain-related guilt are common and important experiences in LBP and are associated with mood and disability.