Niels Grunnet-Nilsson

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.

Cervical spine lesions after road traffic accidents: a systematic review

Study Design. A systematic critical literature review. Objectives. To determine whether occult pathoanatomical lesions in the cervical spine of road traffic fatalities exist and if they can be identified using optimal autopsy techniques. Summary of Background Data. Previous investigations have examined pathoanatomical conditions of the cervical spine of road traffic fatalities. However, different methods of investigation have been used, and results of studies are conflicting. Hence, potential pathoanatomical conditions in fatalities and survivors remain a controversial issue. Methods. Articles were retrieved searching the MEDLINE, Mantis, and Cochrane libraries. Studies examining the cervical spine of road traffic fatalities at autopsy were included and evaluated according to a set of quality criteria. For in-depth review, only studies using surface cryoplaning microtomy autopsy technique and a control group were included. Results. Twenty-seven articles of which three fulfilled the quality criteria were reviewed. In these studies, subtle pathoanatomical lesions were found in the cervical intervertebral discs, cartilaginous endplates, and the articular surfaces and capsules of the zygapophysial joints. The lesions were found exclusively in the traumatized patients and in none of the patients in the control group. Conclusions. Occult pathoanatomical lesions in the cervical intervertebral disc and zygapophysial joints after fatal road traffic trauma may exist. Present imaging methods, especially conventional radiography, do not visualize these subtle lesions; hence, underreporting of pathoanatomical lesions during standard autopsy is probably common. These findings may have clinical relevance in the management of road traffic trauma survivors with potentially similar pathoanatomy.

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.

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.

Secondary legitimacy: a key mainstream health care inclusion strategy for the Danish chiropractic profession?

Chiropractic has matured into a legitimate health care profession in many parts of the world. However, its “outsider” classification of complementary and alternative (CAM) and a relative lack of penetration into ordinary health care services (OHCS) frustrate its efforts of cementing a position among those functioning in the highly contested musculoskeletal health care arena. This tension and consequent moves toward mainstream inclusion have been observed with interest by contemporary social scientists as chiropractic’s professional project is considered a test case, likely to affect other CAM professions with similar aspirations. In this regard, emergent theoretical frameworks such as “boundary work” and “countervailing powers” maintain that professions acting in contested niche areas cannot rely on primary legitimacy based on professional trait characteristics or legislated position (social closure) alone. Rather, the profession must develop more subtle secondary legitimization strategies in order to sustain its position. It is against this backdrop and observations suggesting that chiropractics professional project may have stalled to a certain degree, that we submit the view that secondary legitimacy in the chiropractic context deserves elucidation.