Henrik Hein Lauridsen

Responsiveness and minimal clinically important difference for pain and disability instruments in low back pain patients

BackgroundThe choice of an evaluative instrument has been hampered by the lack of head-to-head comparisons of responsiveness and the minimal clinically important difference (MCID) in subpopulations of low back pain (LBP). The objective of this study was to concurrently compare responsiveness and MCID for commonly used pain scales and functional instruments in four subpopulations of LBP patients.MethodsThe Danish versions of the Oswestry Disability Index (ODI), the 23-item Roland Morris Disability Questionnaire (RMQ), the physical function and bodily pain subscales of the SF36, the Low Back Pain Rating Scale (LBPRS) and a numerical rating scale for pain (0–10) were completed by 191 patients from the primary and secondary sectors of the Danish health care system. Clinical change was estimated using a 7-point transition question and a numeric rating scale for importance. Responsiveness was operationalised using standardardised response mean (SRM), area under the receiver operating characteristic curve (ROC), and cut-point analysis. Subpopulation analyses were carried out on primary and secondary sector patients with LBP only or leg pain +/- LBP.ResultsRMQ was the most responsive instrument in primary and secondary sector patients with LBP only (SRM = 0.5–1.4; ROC = 0.75–0.94) whereas ODI and RMQ showed almost similar responsiveness in primary and secondary sector patients with leg pain (ODI: SRM = 0.4–0.9; ROC = 0.76–0.89; RMQ: SRM = 0.3–0.9; ROC = 0.72–0.88). In improved patients, the RMQ was more responsive in primary and secondary sector patients and LBP only patients (SRM = 1.3–1.7) while the RMQ and ODI were equally responsive in leg pain patients (SRM = 1.3 and 1.2 respectively). All pain measures demonstrated almost equal responsiveness. The MCID increased with increasing baseline score in primary sector and LBP only patients but was only marginally affected by patient entry point and pain location. The MCID of the percentage change score remained constant for the ODI (51%) and RMQ (38%) specifically and differed in the subpopulations.ConclusionRMQ is suitable for measuring change in LBP only patients and both ODI and RMQ are suitable for leg pain patients irrespectively of patient entry point. The MCID is baseline score dependent but only in certain subpopulations. Relative change measured using the ODI and RMQ was not affected by baseline score when patients quantified an important improvement.

Standardized manual palpation of myofascial trigger points in relation to neck/shoulder pain; the influence of clinical experience on inter-examiner reproducibility

A diagnosis of Myofascial Pain Syndrome (MPS) requires palpation for the identification of at least one clinically relevant trigger point (TP). However, few comparable, high quality studies currently exist from which to draw firm conclusions regarding the robustness of TP examination. An inter-observer agreement study was conducted using two experienced and two inexperienced clinicians. All performed standardized palpation of the upper Trapezius musculature, judging the clinical relevance of TP(s) using clinician global assessment (GA). A random case mix of 81 female participants was examined, 14 asymptomatic and the remainder suffering from neck/shoulder pain. Examiners received psychomotor skills training and video feedback analysis to improve protocol standardization. Kappa co-efficient calculations indicated good agreement between the experienced pairing (κ = 0.63), moderate agreement between the mixed pairings (κ = 0.35 and 0.47) and poor agreement between the inexperienced pairing (κ = 0.22). Inter-observer agreement was not stable with the experienced pairing exhibiting a sharp decline in agreement during the latter portion of the study. Identification of clinically relevant TPs of the upper Trapezius musculature is reproducible when performed by two experienced clinicians, however, a mixed observer pairing can yield acceptable agreement. A protracted period of data collection may be detrimental to inter-observer agreement; more investigation is needed in this regard.

Managing Missing Scores on the Roland Morris Disability Questionnaire

Study Design. Analysis of Roland Morris Disability Questionnaire (RMDQ) and Oswestry Disability Index (Oswestry) responses. Objective. To determine the prevalence of unanswered questions on the RMDQ23 (23-item RMDQ version) and Oswestry questionnaires. To determine whether managing RMDQ23 missing data using proportional recalculation is more accurate than simply ignoring missing data. Summary of Background Data. It is likely that the most common method for calculating an RMDQ sum score is to simply ignore any unanswered questions. In contrast, the raw sum score on the Oswestry is converted to a 0 to 100 scale, with the advantage of allowing missing data to be accommodated by proportional recalculation. Methods. The prevalence of unanswered RMDQ23 questions was measured in a research project and a routine care setting. The accuracy of the RMDQ23 proportional recalculation method was measured using 311 fully completed RMDQ23 and matching Oswestry questionnaire sets. Raw sum scores were calculated, and questions systematically dropped. At each stage, sum scores were converted to a score on a 0 to 100 scale and the error calculated. Wilcoxon Tests were used to compare the magnitude of the error scores. Results. The prevalence of people who did not answer one or more questions was 29.5% (RMDQ23) in routine care, and 13.9% (Oswestry) and 20.3% (RMDQ23) in a research project. Proportional recalculation was a more accurate method to calculate RMDQ sum scores than simply ignoring missing data, when two or more questions were unanswered. Conclusion. Because of less error when missing data are present, the most accurate method for expressing RMDQ sum scores collected using Yes/No answers is conversion to a 0 to 100 scale. This conversion method is (a) if all questions are answered or only one question is unanswered, multiply the raw sum score by 100 divided by the total number of questions, and (b) if two or more questions are unanswered, multiply the raw sum score by 100 divided by the number of answered questions.

Choice of external criteria in back pain research: Does it matter? Recommendations based on analysis of responsiveness.

Abstract Understanding a change score is indispensable for interpretation of results from clinical studies. One way of determining the relevance of change scores is through the use of transition questions that assesses patients’ retrospective perception of treatment effect. Unfortunately, results from studies using transition questions are difficult to compare since wording of questions and definitions of important improvements vary between studies. The objectives of this study were to determine the consequence of using different transition questions on pain and disability measures and make proposals for a standardised use of such questions. Two hundred and thirty‐three patients with low back pain and/or leg pain were recruited. Participants were followed over an 8‐week period and randomised to two groups receiving a 7‐ (TQ1) and 15‐point (TQ2) transition question, respectively, in addition to a numeric rating scale evaluating the importance of the perceived change. Four external criteria were generated using both stringent and less stringent standards to dichotomise patients. Discrimination was determined using area under the receiver operating characteristic curve (ROCauc) and responsiveness using standardised response mean (SRM). Results demonstrated small variations in ROCauc across the external criteria for all outcome measures. 7% more patients were classified as improved in the group receiving the 15‐point TQ compared to the 7‐point TQ (stringent standard). SRMs were higher for the retrospective TQs in primary sector patients compared to the serial measures with no difference between TQ1 and TQ2. On the basis of our findings we have outlined a proposal for a standardised use of transition questions.

Reporting outcomes of back pain trials: A modified Delphi study

Background: Low back pain is a common and expensive health complaint. Many low back pain trials have been conducted, but these are reported in a variety of ways and are often difficult to interpret.

What is an acceptable outcome of treatment before it begins? Methodological considerations and implications for patients with chronic low back pain.

Understanding changes in patient-reported outcomes is indispensable for interpretation of results from clinical studies. As a consequence the term “minimal clinically important difference” (MCID) was coined in the late 1980s to ease classification of patients into improved, not changed or deteriorated. Several methodological categories have been developed determining the MCID, however, all are subject to weaknesses or biases reducing the validity of the reported MCID. The objective of this study was to determine the reproducibility and validity of a novel method for estimating low back pain (LBP) patients’ view of an acceptable change (MCIDpre) before treatment begins. One-hundred and forty-seven patients with chronic LBP were recruited from an out-patient hospital back pain unit and followed over an 8-week period. Original and modified versions of the Oswestry disability index (ODI), Bournemouth questionnaire (BQ) and numeric pain rating scale (NRSpain) were filled in at baseline. The modified questionnaires determined what the patient considered an acceptable post-treatment outcome which allowed us to calculate the MCIDpre. Concurrent comparisons between the MCIDpre, instrument measurement error and a retrospective approach of establishing the minimal clinically important difference (MCIDpost) were made. The results showed the prospective acceptable outcome method scores to have acceptable reproducibility outside measurement error. MCIDpre was 4.5 larger for the ODI and 1.5 times larger for BQ and NRSpain compared to the MCIDpost. Furthermore, MCIDpre and patients post-treatment acceptable change was almost equal for the NRSpain but not for the ODI and BQ. In conclusion, chronic LBP patients have a reasonably realistic idea of an acceptable change in pain, but probably an overly optimistic view of changes in functional and psychological/affective domains before treatment begins.

The Otitis Media-6 questionnaire: psychometric properties with emphasis on factor structure and interpretability

BackgroundThe Otitis Media-6 questionnaire (OM-6) is the most frequently used instrument to measure health related quality of life in children with otitis media. The main objectives of this study are 1) to translate and cross-culturally adapt the OM-6 into Danish, and 2) to assess important psychometric properties including structural validity and interpretability of the OM-6 in a Danish population of children suffering from otitis media.MethodsThe OM-6 was translated and cross-culturally adapted according to international guidelines. A longitudinal validation study enrolled 491 children and their families, and the measurement properties of the OM-6 were evaluated using the Cosmin taxonomy. The properties assessed were construct and structural validity (confirmatory factor analysis) including internal consistency, reproducibility (test-retest reliability and smallest detectable change), responsiveness and interpretability.ResultsA total of 435 children were eligible to participate in the study. Analyses of structural validity and internal consistency indicated that parent appraisal of hearing and speech problems may be problematic. Both scales showed similarly good test-retest reliability and construct validity, were able to discriminate between diagnostic subgroups and responsive to change. Cut-off values of 16.7 and 30.0 were found to represent minimal important change for the patients.ConclusionsThe Danish version of the OM-6 is a reliable, valid, responsive and interpretable questionnaire to measure quality of life in children with otitis media. This study sheds light on possible weaknesses of the instrument that needs to be acknowledged in the utilization of the instrument. However, despite these issues our results support the continuing use of OM-6 as a 1-factor functional health scale with a separate global health rating. Furthermore, indications of values representing minimal important change as perceived by the respondent are presented.

Development of the young spine questionnaire

BackgroundBack pain in children is common and early onset of back pain has been shown to increase the risk of back pain significantly in adulthood. Consequently, preventive efforts must be targeted the young population but research relating to spinal problems in this age group is scarce. Focus has primarily been on the working age population, and therefore specific questionnaires to measure spinal pain and its consequences, specifically aimed at children and adolescents are absent. The purpose of this study was to develop a questionnaire for schoolchildren filling this gap.MethodsThe Young Spine Questionnaire (YSQ) was developed in three phases – a conceptualisation, development and testing phase. The conceptualisation phase followed the Wilson and Cleary model and included questions regarding spinal prevalence estimates, pain frequency and intensity, activity restrictions, care seeking behaviour and influence of parental back trouble. Items from existing questionnaires and the “Revised Faces Pain Scale” (rFPS) were included during the development phase. The testing phase consisted of a mixed quantitative and qualitative iterative method carried out in two pilot tests using 4th grade children and focusing on assessment of spinal area location and item validity.ResultsThe testing phase resulted in omission of the pain drawings and the questions and answer categories were simplified in several questions. Agreement between the questionnaire prevalence estimates and the interviews ranged between 83.7% (cervical pain today) and 97.9% (thoracic pain today). To improve the understanding of the spinal boundaries we added bony landmarks to the spinal drawings after pilot test I. This resulted in an improved sense of spinal boundary location in pilot test II. Correlations between the rFPS and the interview pain score ranged between 0.67 (cervical spine) and 0.79 (lumbar spine).ConclusionsThe Young Spine Questionnaire contains questions that assess spinal pain and its consequences. The items have been tested for content understanding and agreement between questionnaire scores and interview findings among target respondents. These preliminary results suggest that the YSQ is feasible, has content validity and is a well understood questionnaire to be used in studies of children aged 9 to 11 years.

Quality-of-Life Differences among Diagnostic Subgroups of Children Receiving Ventilating Tubes for Otitis Media

Objective The pathological picture may differ considerably between diagnostic subgroups of children with otitis media receiving ventilating tubes. The aims of this study are to investigate differences in quality of life among diagnostic subgroups of children treated with ventilating tubes and to investigate possible predictors for clinical success. Study Design Longitudinal observational study. Setting Secondary care units. Methods Four hundred ninety-one families were enrolled in the study. The Otitis Media–6 questionnaire was applied in the assessment of child quality of life. Caregivers completed questionnaires at 7 time points from before treatment to 18-month follow-up. Logistic regression analysis was used to investigate possible predictors for clinical success. Results Response rates ranged from 96% to 81%; diagnostic distribution: 15% recurrent acute otitis media (rAOM), 47% otitis media with effusion (OME), and 38% mixed diagnosis of rAOM and OME (rAOM/OME). There were no significant differences between children diagnosed with rAOM and children diagnosed with rAOM/OME. However, these children had a significantly poorer quality of life at baseline compared with children diagnosed with only OME. Factors associated with clinical success included a diagnosis of rAOM, number of interrupted nights, physician visits, and canceled social activities due to OM. Conclusions Results highlight the importance of distinguishing between diagnostic subgroups of children having ventilating tube treatment. A diagnosis of rAOM was found to predict baseline quality of life. Children with rAOM with or without OME were found to suffer significantly more than children with only OME before treatment. Factors associated with disease severity were found to predict clinical success.

Caregiver Quality of Life and Daily Functioning in Relation to Ventilating Tube Treatment

Objective Caregiver quality of life and daily functioning may improve after ventilating tube treatment in children with otitis media. The aims of this study are to assess possible changes in caregiver quality of life and daily functioning in relation to ventilating tube treatment and to investigate possible predictors for clinical success. Study Design Longitudinal observational study. Setting Secondary care units. Methods Four hundred ninety-one families were enrolled in the study. The Caregiver Impact Questionnaire was applied in the assessment of caregiver quality of life. Caregivers completed questionnaires at baseline and at 1, 3, 6, 12, and 18 months’ follow-up. Variables on caregiver daily functioning comprised 4 weeks’ history of number of interrupted nights, absenteeism, cancelled social activities, and doctor visits as a result of otitis media in the child. Results Response rates ranged from 96% to 79%. Significant improvements in disease-specific quality of life were seen after treatment. The poorest baseline quality of life was found in caregivers of children with recurrent acute otitis media. Significant improvements were found on all variables on daily functioning. Predictors for caregiver-perceived clinical success included child sex, number of interrupted nights, doctor visits, absenteeism, and cancelled social activities. Conclusion Results of this study support the notion that caregivers of children with otitis media with defined surgical indications improve their quality of life and daily functioning after ventilating tube treatment. Factors related to caregiver functioning and disease severity were found to be associated with caregivers experiencing important improvements after treatment.