A Randomized Controlled Trial Investigating the Impact of Disease Labels on the Public’s Perceptions About Calcium Pyrophosphate Deposition (CPPD) Disease

Background and Objectives: The nomenclature of calcium pyrophosphate deposition (CPPD) disease remains confusing, with different labels used interchangeably to describe the disease. Although ‘CPPD disease’ is the term that has been recommended by EULAR since 2011, ‘pseudogout’ remains the most frequently used label in the medical literature. This study aimed to investigate how the labels ‘CPPD disease’ versus ‘pseudogout’ affect the public’s perceptions of the illness. Methods: In this randomized controlled single-blind study, 200 members of the public watched a 2 min video describing a form of arthritis labeled as either ‘CPPD disease’ or ‘pseudogout’. Participants then completed a questionnaire assessing their perceptions of the illness using the Brief Illness Perception Questionnaire (BIPQ), with additional questions about their perceived seriousness of the illness and embarrassment associated with it, and beliefs about causes and management strategies. The primary outcome was the level of embarrassment associated with the illness. Results: Overall, embarrassment scores were low with no significant difference between the ‘CPPD disease’ and ‘pseudogout’ groups. Participants in both groups viewed the illness as being serious. There were no differences between the groups in their responses to the BIPQ, nor in their beliefs on the likely causes and management strategies. Even after a video intervention, participants’ understanding of the illness remained low. Conclusions: The labels ‘CPPD disease’ and ‘pseudogout’ do not differentially influence perceptions about the illness among members of the public. This could be due to the lack of knowledge about CPPD disease, highlighting the need to increase public awareness of this important condition.