American and Dutch patients with Cushing’s syndrome have different ways of interpreting the same items on a disease-specific quality-of-life (QoL) questionnaire, research shows.
Cushing’s syndrome is debilitating physically, mentally, and often emotionally. Even with successful treatment, long-term residual effects have been observed on the quality of life of Cushing’s patients, with many reporting more pain and diminished well-being in general.
QoL assessment is an important outcome measure to evaluate the effects of chronic illness, such as Cushing’s syndrome, as well as the effect of any treatment.
However, one’s set of beliefs, moral values, traditions, language, and laws influence how a patient assesses his or her quality of life.
“The CushingQoL is a widely used disease-specific questionnaire to assess QoL in patients with Cushing’s syndrome. However, there is no information about potential cross-country differences in the way patients interpret the items on the CushingQoL,” the scientists wrote.
A team from the University of California sought to investigate if the CushingQoL was interpreted similarly by patients with distinct nationalities.
They recruited 260 American and 103 Dutch patients with Cushing’s syndrome who answered CushingQoL and a short demographics survey, both in an online format.
CushingQoL consists of 12 items measured on a 5-point scale assessing how often or how much each item has been experienced by the patient in the previous four weeks.
Survey questions reflect physical aspects (e.g., “I bruise easily”), psychological aspects (e.g., “I am more irritable, I have sudden mood swings and angry outbursts”), and social aspects (e.g., “I have had to give up my social or leisure activities due to my illness”). The test score ranges from 0-100, with a lower score indicating a greater impact on QoL.
Results showed that three of the 12 CushingQoL questions were interpreted differently by the U.S. and Netherlands groups.
Dutch patients were more likely to report that they experience lingering effects of the disease on their daily lives, while American patients more frequently expressed worry about their future health.
All three items were related to psychosocial issues (e.g., irritable mood, everyday activities, and worrying about one’s health). Questions evaluating physical aspects of QoL did not vary between groups.
“Interpreting results from the CushingQoL requires careful consideration of country of residence, as this appears to impact the interpretation of the questionnaire,” researchers concluded.
More research is necessary, they said, to investigate if CushingQoL interpretations vary across nationalities and beyond this study’s population.