OBJECTIVES: To develop a novel patient reported outcome (PRO) measure to assess the impact of nocturia (defined as getting up to void at least once per night) on sleep, sensitive to detect treatment benefits and aligned with the FDA PRO guidance.
METHODS: The Nocturia Sleep Quality Scale (NSQS) was developed through a rigorous process including a targeted literature review to identify sleep-related concepts. Next in-depth concept elicitation (CE) interviews were conducted with patients with a clinical diagnosis of nocturia. Using results of both the literature review and CE interviews, draft items were generated to address concepts identified as important, meaningful, and relevant. Items were further refined through three iterative sets of cognitive debriefing (CD) interviews with a new sample of patients to optimize instructions, question wording, and response options. Input was also sought from two external sleep research experts.
RESULTS: Results of the literature review combined with data from 18 CE interviews provided the basis for a comprehensive set of concepts. Constant comparative analysis was used to identify themes and support item development. The draft questionnaire consisted of 15 items and 9 scales for testing. Wording and scaling of the NSQS items was optimized based on feedback from the 22 CD interviews. Finally, CD participants confirmed completeness and relevancy of the NSQS providing support for the content validity and ability of items to reflect patient perception of nocturia-related sleep impacts.
CONCLUSIONS: The NSQS is a brief measure designed to assess the impact of nocturia on sleep. The NSQS consists of 6 items assessing nighttime awakenings, sleep quantity, and sleep quality and employs a short recall period of the night before. The NSQS is self-administered and is intended to assess change after treatment in a standardized manner. Psychometric evaluation is underway to describe key measurement properties.
