Assessing the psychometric properties of the British Columbia pain behaviour taxonomy (BCPBT).

A new observational pain behaviour taxonomy, the British Columbia Pain Behaviour Taxonomy (BCPBT), was developed by modifying a previously existing taxonomy created by Keefe and Block (1982). The BCPBT was designed to be consonant with recent research findings and the pragmatic concerns of the Workers’ Compensation Board of British Columbia (WCB-BC), for whom the modifications were made. A series of six studies was conducted to analyze the psychometric properties of this new measure. In Study 1, the BCPBT was assessed for accuracy of application over time. A multiplebaseline design was used to measure the extent to which a select group of judges could master the taxonomy. Training in the BCPBT was staggered, with the Immediate Training group receiving the first 5-hour training seminar. Judges had moderately high agreement scores on the pretest; the training seminar did improve coding agreement, but these improvements failed to reach statistical significance. However, all judges did eventually reach an adequate level of coding proficiency (mean agreement = 83%, k = .66). Study 2 involved the demonstration of test-retest reliability across judges trained in the BCPBT over a maximum delay of two weeks; a mean Pearson product-moment correlation was computed incorporating all post-training percent agreement scores (mean r = .89), indicating a high level of reliability over time. In Study 3, judges were tested on their retention of the taxonomy five months after their first exposure, and feedback of their performances was given in an attempt to increase mean percent agreement. It was determined that trained judges could surpass the minimum agreement criterion of 80% (mean agreement = 83.8%, k = .67), but were unable to reach a mean agreement of 90%, a criterion that has been used by past researchers . In Studies 4A and 4B, WCB-BC Properties of the BCPBT iv judges trained in the BCPBT were shown to achieve adequate agreement levels after one training session, both in an experimental setting (mean agreem ent4A = 80.9%, k = .62), and in a clinical setting (mean a g r e e m e n t4B = 87.7%, k = .69). For Study 5, the scores of 67 patients who had been administered the BCPBT twice within a three day period were used to assess the test-retest reliabilities of the measure and each behavioural category. The results indicated that facial expression, guarding, and total pain behaviour score had strong relationships over time, while the remaining behavioural categories had moderately sized correlations. Study 6 focused on refining the BCPBT's psychometric properties by assessing its internal consistency and component structure using the data collected from 120 WCB-BC claimants. Using Cronbach's alpha, the BCPBT was streamlined by removing all items that had consistently low item-total correlations. Principal components analysis revealed a strong underlying component structure for four of the five behavioural types. On the strength of all the combined information gathered over the six separate studies, it appears that the BCPBT is easy to learn, and demonstrates satisfactory inter-rater and test-retest reliability. The psychometric changes made to the BCPBT in response to the internal consistency and component structure information generated by Study 6 must be examined in subsequent research. Properties of the BCPBT TABLE OF CONTENTS Abstract iii List of Tables viii List of Figures ix Acknowledgement x Introduction 1 The Low Back Disability Project 6 Previous Pain Behaviour Observational Systems 12 The Behavioural Assessment Protocol 23 The British Columbia Pain Behaviour Taxonomy (BCPBT) 25 The Present Studies 30 Study 1 Validation of the Training Protocol for the BCPBT 31 Method 32 Judges 32 Materials 32 Training 32 Testing 33 Equipment 34 Design 35 Procedure 35 Training 36 Data scoring 38 Data analysis 39 Results 39 Study 2 Test-retest Reliability of the UNBC Judges 45 Method 45 Judges 45 Materials 45 Design and procedure 46 Data scoring 46 Results 46 Study 3 The Effect of Feedback on BCPBT Accuracy 48 Method 49 Judges 49 Materials 49 Design and procedure 49 Properties of the BCPBT vi Data scoring 50 Results 50 Study 4 Part I: Effects of Training on WCB Judges 52 Method 52 Judges 52 Materials 52 Design and procedure 53 Data scoring 53 Results 53 Part n: Using the BCPBT in a Clinical Setting 54 Method 54 Judges 54 Materials 54 Design and procedure 55 Data scoring 57 Results 57 Study 5 Clinical Test-Retest Reliability of the BCPBT 58 Method 58 Judges 58 Design and procedure 59 Data scoring 59 Results 60 Study 6 Part I: The Internal Consistency of the BCPBT 63 Method 63 Judges 63 Design and procedure 64 Data scoring 64 Results 64 Part II: The Factor Structure of the BCPBT 71 Method 71 Judges 71 Design and procedure 71 Data scoring 72 Data screening 72 Discussion Results 73 Reliability 83 Internal Consistency 83 Principal Components Analyses 89 Properties of the BCPBT Future Directions 92 References 94 Appendix A Informed Consent Form for Study 1 110 Appendix B Informed Consent Form for Study 3 114 Appendix C Brief Coding Manual 117 Appendix D Extended Coding Manual 123 Appendix E Experimental Coding Form 137 Appendix F WCB Coding Manual Additions 139 Appendix G WCB Coding Form 150 Properties of the BCPBT viii