Development of the Impact of Nighttime Urination (INTU) questionnaire to assess the impact of nocturia on health and functioning.

AIMS: This study describes development of the Impact of Nighttime Urination (INTU) questionnaire to assess nocturia impacts on health and functioning.

METHODS: Development of the questionnaire followed an iterative patient-directed process as recommended by current guidance for patient-reported outcome (PRO) measures. An initial 15-item questionnaire was devised based on reviewing the published literature, and then modified through four rounds of semi-structured interviews of 28 individuals with nocturia. In each round, open-ended concept elicitation, followed by cognitive debriefing, was used to assess the questionnaire. Items were modified based on participants' responses and incorporated into the next round of interviews.

RESULTS: In all rounds, participants reported that their experiences were easy to recall and report on a daily basis and that the burden of completing the questionnaire was low. The final questionnaire has a same-day recall period. It includes six daytime impact items-having limited concentration, a sense of feeling tired, difficulty getting things done, irritability, not feeling rested, and drowsiness-and four items that measure the nighttime impact of nocturia-patient concern, waking up too early, difficulty getting enough sleep, and feeling bothered by having to get up at night to void. Responses follow a 5- or 4-point scale. The final INTU captures the key concepts associated with nocturia as confirmed by cognitive debriefing.

CONCLUSIONS: Development of the 10-item INTU, a nocturia-specific PRO measure, was based on direct input and feedback from patients and has demonstrated that it captures the patient-reported impacts of nocturia.