Development and validation of a polycystic liver disease complaint-specific assessment (POLCA)

Polycystic liver disease (PCLD) may lead to extensive hepatomegaly and invalidating complaints. Therapeutic decisions, including somatostatin-analogues (SAs) and (non)-transplant surgery are besides the existence of hepatomegaly, also guided by the severity of complaints. We developed and validated a self-report instrument to capture the presence and severity of disease specific complaints for PCLD.

The study population consisted of 129 patients. Items for the PCLD-complaint-specific assessment (POLCA) were developed based on the chart review of symptomatic PCLD patients (n=68) and literature, and discussed during expert-consensus-meetings. 61 patients who needed therapy were asked to complete the POLCA and the short form health survey version 2 (SF36V2) at baseline and after 6 months of SA-treatment. CT-scans were used to calculate liver volumes (LV). Factor analysis was conducted to identify subscales and remove suboptimal items. Reliability was assessed by Cronbach's alpha. Convergent, criterion validity and responsiveness were tested using prespecified hypotheses.

In the validation group (n=61), 47 received lanreotide (LAN) and 14 were offered LAN as bridge to liver transplantation (LTx). Factor analysis identified four subscales, which correlated with the physical component summary (PCS). Baseline POLCA scores were significantly higher in LTx-listed patients. In contrast to SF36V2, POLCA-paired observations in 47 patients demonstrated that 2 subscales were lowered significantly and 2 borderline. LV reduction of ⩾ 120 ml resulted in a numerical, more pronounced relative decrease of all scores.

In contrast to SF36V2, the POLCA shows good validity and responsiveness to measure complaint severity in PCLD.