OBJECTIVES: PLD is a rare condition in which multiple cysts develop in the liver. Approximately 20% of patients experience a high symptom burden. Limited patient-centered research exists for this condition, and much of the patient-reported data results from generic measures. To address this gap, a disease-specific PROM, the PLD-Symptom was developed.

METHODS: A non-interventional, qualitative study following FDA guidelines was conducted. Data were collected from the literature and individual telephone interviews, following semi-structured interview guides, with 4 clinical experts and 30 adult respondents (United States and United Kingdom). Information was coded based on adapted grounded theory. A draft theoretical model of PLD signs/symptoms and draft items were generated, underwent translatability assessment, and were cognitive debriefed (n=12) employing “think aloud” methodology.

RESULTS: Respondents were mostly female (77%), average age 51.2 (range, 32-72), 67% had polycystic kidney disease, and average time to initial diagnosis 8.5 years (range, 0-25). Experts (3 hepatologists, 1 nurse) identified 21 symptoms in total. All but 3 of these were also reported by respondents who reported 40 symptoms in total. Saturation (95%) was reached by the 19th interview. Symptoms most frequently reported included bloating (n=27, 90%), abdominal/stomach pain (n=26, 87%), tired/low energy (n=25, 83%), and abdominal/stomach increase (n=25, 83%). Symptoms were included in the draft measure if endorsed by at least 40% of participants (or 35-39% if high conceptual importance), rated bothersome by most respondents, experienced at least once a week by most respondents, potentially responsive to treatment, and proximal symptoms. Eleven symptoms met criteria for inclusion. Cognitive debriefing resulted in a validation-ready, 10-item measure. All final items and instructions were found to be relevant, understandable, and consistent with the intended meaning.

CONCLUSIONS: The PLD-Symptom can be considered to have strong content validity based on the concept elicitation data. Psychometric validation is now needed to confirm measurement properties.