Validation of the Modified Brief Pain Inventory-Exploratory Form in Surgery Patients
Abstract
Objective
An exploratory version of the Modified Brief Pain Inventory (mBPI-e) to measure acute post-operative pain, with new items on coughing, breathing, and concentration, was examined for their measurement properties.
Study Design
This is a secondary study using data from two randomized clinical trials: general surgery trial (N=1050) and coronary artery bypass graft (CABG) surgery trial (N=1636). The measurements used in the two trials were: 1) mBPI-e; 2) clinician and patient global evaluations of medications; and 3) pain intensity diary. The mBPI-e and pain intensity were collected for 10 days. Clinician and patient global evaluations of medication were collected twice. The analyses conducted were: 1) exploratory factor analysis (EFA); 2) confirmatory factor analysis (CFA); 3) item response theory (IRT); 4) internal consistency; 5) test-retest reliability; 6) concurrent validity; 7) known-group validity; and 8) responsiveness.
Results
Pain severity, pain interference, and coughing and breathing factors were identified. Pain severity and pain interference subscale scores were constructed for mBPI-e. IRT analyses showed all items exhibited good item characteristics. Internal consistency was 0.85 for severity and 0.87 for interference. Test-retest reliability was 0.81 for severity and 0.71 for interference. Both severity and interference scores were correlated with diary-based pain intensity ratings (P <.0001). Mean severity and interference scores varied by physician and patient global ratings (P <.05). Severity and interference scores were responsive to changes in pain diary scores and physician global ratings (P <.001). There were no substantive differences in reliability or validity for sub-samples of surgery patients.
Conclusions
The original BPI has been used in clinical studies, and the mBPI has demonstrated good reliability and validity in CABG patients. Based on this study, the mBPI-e has also demonstrated good reliability and validity for assessing postoperative acute pain in CABG and general surgery patients.
Keywords: Brief pain inventory, Measurement of pain, Modified brief pain inventory, Pain measure, Post operative pain
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The clinical trial data used in this work were provided by Pfizer, who supported and conducted the 2 clinical trials.
The BPI and mBPI are copyrighted by Charles Cleeland at M.D. Anderson Cancer Center, the University of Texas, Houston. For those interested in using the mBPI-e in their research, permission should be secured from Dr. Cleeland, given that the mBPI-e was developed based on the mBPI instrument.
Conflicts of interest: The work reported here was performed under contract for Pfizer by United BioSource Corporation. Authors WHC, RH, and DR work for the United BioSource Corporation, which performed this work under contract. Author KSC, faculty of the Department of Health Policy and Management, Johns Hopkins Bloomberg School of Public Health, is a contracted consultant to United BioSource Corporation. TJG, faculty of the Department of Anesthesiology, Duke University Medical Center, is an external reviewer with no contractual arrangement with either United BioSource Corporation or Pfizer. CC is an employee of Pfizer. ML was an employee of Pfizer at the time this manuscript was written.
PII: S1877-1319(10)00002-9
doi:10.1016/j.ehrm.2010.04.001
© 2010 Elsevier Inc. All rights reserved.
