A Heat Sensitivity Scale for People with Parkinson's Disease.

Background: People living with Parkinson's disease (PD) commonly experience heat sensitivity-worsening symptoms and restricted daily activities in heat.

Objective: This study aimed to develop a scale of heat sensitivity for people with PD.

Methods: Through a search of the scientific literature and online forums, we developed 41 items relating to experiences of heat for people with PD to assess heat sensitivity. A panel of experts was then consulted to review the scale items critically. After two rounds of review, the scale was refined to 36 items with an overall scale content validity index of 0.89. Via an online survey, 247 people with PD responded to the items.

Results: The items were examined with exploratory factor analysis to determine the underlying factors therein. After several iterations, a simple structure was achieved with 29 items loading uniquely onto one of four factors: daily activities, sweating and exercise, heat-related illness, and symptoms and medications. The model had acceptable to excellent fit statistics (root mean square error of approximation = 0.073 [90% confidence interval 0.067-0.081], root mean square of the residuals = 0.03, comparative fit index = 0.93, and Tucker-Lewis index = 0.91), and each factor showed high reliability (Cronbach's α ≥0.89). Factor and total scale scores were significantly higher among those reporting sensitivity to heat and poor health status.

Conclusion: This new heat sensitivity scale for people living with PD can enable health professionals and clients to assess the severity and impact of heat sensitivity.