Reply to: “Development and validation of a polycystic liver disease complaint-specific assessment (POLCA) – Use of the Delphi technique for content validation”
Authors: Frederik Temmerman, Frederik Nevens
Journal: Journal of Hepatology (2014)

Development and validation of a polycystic liver disease complaint-specific assessment (POLCA) – Use of the Delphi technique for content validationJournal of HepatologyVol. 62Issue 4PreviewTemmerman and collaborators conducted the development and validation of a measurement tool to assess complaints related specifically to polycystic liver disease (PCLD) [1]. Their study is well-written and reasoned, presenting statistical evidence to support the tool responsiveness in the measurement of PCLD complaints. Full-Text PDF Open AccessDevelopment and validation of a polycystic liver disease complaint-specific assessment (POLCA)Journal of HepatologyVol. 61Issue 5PreviewPolycystic 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. Full-Text PDF We welcome the comment by Trevisol et al. on our recent published article “Development and validation of a Polycystic Liver Disease Specific Assessment (POLCA)” [[1]Temmerman F. Dobbels F. Ho T.A. Pirson Y. Vanslembrouck R. Coudyzer W. et al.Development and validation of a polycystic liver disease complaint-specific assessment (POLCA).J Hepatol. 2014; 61: 1143-1150Abstract Full Text Full Text PDF PubMed Scopus (21) Google Scholar]. We appreciate that the authors underscored our intentions to fulfill the main assumptions underlying the validation processes of a questionnaire, including content-, construct- and criterion validity; and reliability. The authors ask additional information concerning the applied method for “content validation”. In this regard, we want to reply concisely. In brief, patients with polycystic liver disease (PCLD) may develop severe hepatomegaly and this may become very disabling. The interpretation of complaints expressed by these patients in terms of severity and impact on the health related quality of life is subjective but crucial, as decisions on medical treatment and even indication for liver transplantation are partially based on the severity of the reported complaints and, therefore, we developed and psychometrically validated the POLCA. We first organized a general informative session in which the conceptual framework defining the item generation process and psychometric properties. For content validation, we used the Nominal Group technique, in which the professional judgement by experts was guided by: an analysis of medical records from 68 patients including the transcripts of social workers and by a review of the literature. The board consisted of experts with different expertise dealing with these patients: hepatologists, nephrologists and abdominal transplant surgeons. In addition, experts both from a Dutch and French speaking tertiary center participated. Three consensus meetings were needed to downgrade the initial 27 items into 16 items. Based on that list, the POLCA questionnaire was compiled, which was again fine-tuned by phone conferences, and e-mail, to allow for comprehensiveness and clarity. All participants approved the final version. By doing this, we are convinced that we could overcome the limitations of the “Nominal group technique” that in one face-to-face meeting one expert influences the others. As was mentioned in the paper, severe symptomatic PCLD is a rare disease, and such pretesting of the questionnaire in symptomatic PCLD patients was not performed in order not to lose patients for the instrument’s validation. The validation of self-report instruments is a complex, continuous process and there is obviously a need for further studies. Further validation of the POLCA is currently being performed in 20 Belgian hospitals and data are expected within 2 years (BE322201422560). The authors declared that they do not have anything to disclose regarding funding or conflict of interest with respect to this manuscript.