Further validation of the psychometric properties of the Bowel Function Index for evaluating opioid-induced constipation (OIC)

Abstract

Objective:

The BFI (Bowel Function Index) is a 3-item questionnaire for assessing opioid-induced constipation (OIC). The aim of this study was to contribute to the validation of the psychometric properties of the BFI by confirming a constipation threshold, and through correlation with other validated tools: KESS (Knowles Eccersley Scott Symptom) score and generic (12-Item Short Form Health Survey, SF-12) and specific (Patient Assessment of Constipation–Quality of Life, PAC-QoL) quality-of-life scores.

† BFI Copyright 2002, Mundipharma GmbH, City, Country; BFI is subject of European Patent Application Publication No. EP 1,860,988 and corresponding patents and applications in other countries.

* PAC-QOL, Janssen Global Services, LLC, City, State, Country, USA.

Methods:

A survey on opioid-requiring cancer-patients was carried out in France. A questionnaire was filled out for all patients that recorded their demographic characteristics, an assessment of their constipation using BFI and KESS scores, and included a self-assessment of quality-of-life using PAC-QoL and SF-12. Correlation of BFI with KESS, PAC-QoL, and SF-12 was investigated.

Results:

Five hundred and twenty patients participated in the entire data collection with no loss. BFI was shown to be statistically correlated (r = 0.571; p < 0.0001) with the KESS score and matches up with PAC-QoL and to a lesser extent with the SF-12 generic quality-of-life questionnaire. A BFI threshold of 27–29 to discriminate constipated from non-constipated patients was confirmed.

Key limitations:

This cross-sectional study in a selected population of cancer pain patients has validated the psychometric properties of the BFI. Further confirmation of the validity of the BFI could be sought through the use of longitudinal studies, and larger populations, such as non-cancer pain patients treated with opioids.

Conclusion:

This study contributes to the validation of the psychometric properties of the BFI. It confirms the BFI as an easy-to-use tool to assess constipation and its impact on quality-of-life in chronic pain patients.

Keywords::

• Constipation
• Opioids
• BFI
• KESS
• Quality-of-life
• SF-12
• PAC-QoL

Transparency

Declaration of funding

This study was designed and financed by Mundipharma SAS France, and conducted under the sponsorship of Mundipharma SAS France.

Declaration of financial/other interests

LA and SP were principal co-ordinators of this study and have received fees from Mundipharma: LA was a short-term board member for Mundipharma SAS France and SP was a board member for Mundipharma SAS. NB participated as an investigator in this study. NB has received fees as a speaker for a Mundipharma symposium. BC was an employee of Mundipharma SAS France. CC is an employee of Mundipharma SAS France. All authors had full access to the data and were involved in the development and writing of the manuscript. All authors made substantial contributions to conception and design, or acquisition of data, or analysis and interpretation of data; critically reviewed the manuscript and have provided final approval of the version to be published. JME Peer Reviewers on this manuscript have no relevant financial relationships to disclose.

Acknowledgements

The authors thank all those involved in conducting this study. Editorial support was provided by Catharina Buschmann-Kramm of Mundipharma Research GmbH & Co. KG.

Notes

† BFI Copyright 2002, Mundipharma GmbH, City, Country; BFI is subject of European Patent Application Publication No. EP 1,860,988 and corresponding patents and applications in other countries.

* PAC-QOL, Janssen Global Services, LLC, City, State, Country, USA.