1.1

Introduction

Many functional disability scales have been prompted by research and medical care in the field of low back pain (LBP) in general and its chronic form in particular . The Oswestry Disability Questionnaire, the Quebec Back Pain Disability Scale (QBPDS), the Roland-Morris Disability Questionnaire and the Dallas Pain Questionnaire (DPQ) are the best known tools but none has prevailed as the “gold standard” – notably in terms of the metrological criteria (reliability, validity, feasibility, etc.) needed to justify the choice of a measurement scale.

However, the two most recently developed tools (the QBPDS and the DPQ ) have been shown to be both reliable and valid. The LBP-specific QBPDS self-questionnaire for functional evaluation was developed and validated by Kopec in English and in Canadian French. It takes account of pain-related functional limitations and monitors changes over time in LBP patients participating in rehabilitation programmes. This scale has proven metrological properties (i.e. reliability, reproducibility and validity of construction) in LBP patients and is considered to be suitable for measuring different levels of functional disability. The QBPDS is also very easy and rapid to complete (3 to 5 min) and is appropriate for use in France, despite the presence of a few terms that are more characteristic of Canadian French . However, the QBPDS’s sensitivity to change, the predictive validity of the initial scores and its usefulness in longitudinal evaluations remain to be described (notably for the French-language version) .

The DPQ is a self-questionnaire based on a cognitive and behavioural conception of chronic pain. It was designed to evaluate the impact of LBP on everyday life ; its field of investigation goes beyond physical disability and addresses the social interest domain. The DPQ’s metrological properties (reliability, reproducibility, validity of content, validity of construction, discriminant power and predictive validity) have been confirmed in LBP sufferers . However, the original American English version has not been investigated in terms of sensitivity to change. In the French-language version , sensitivity to change has been demonstrated for the “daily living”, “work-leisure”, and “anxiety/depression” domains but not for the “social interest” domain .

In the present study, we set out to evaluate the QBPDS’s sensitivity to change (and to compare it with that of the DPQ) in a population of LBP sufferers participating in a functional rehabilitation programme.

1.2

Methods

1.3

Results

1.4

Discussion

Our retrospective study on a sample of 30 chronic LBP subjects evaluated before and after a back functional rehabilitation programme showed that the QBPDS displayed high sensitivity to change, whereas that of the DPQ was moderate. However, our study had a number of limitations: the population (30 subjects) was quite small and our analysis was based on the retrospective examination of medical records filled out by physicians and physiotherapists, with some data loss. Some sets of records were not fully exploitable. On the methodological level, it would have been interesting to calculate the minimum clinical change ; however, this would have required a different methodology (i.e. a prospective study).

In contrast, our population was characteristic of a “hospital population” on whom chronic LBP had a significant socioprofessional impact; 22 of the 30 patients were off work (sick leave, workplace accident, invalidity, etc.).

The overall results of the functional rehabilitation programme were similar to those reported in the literature. However, the goal of the present study was not to evaluate the efficacy of this programme, even though knowledge of the outcome was important for describing our results on the scales’ sensitivity to change. Even though many authors have underlined the generally positive effects of functional rehabilitation programmes, there is no consensus on this matter and the conclusions vary according to the parameters evaluated. Most studies have reported an improvement in clinical variables (pain intensity, mobility and muscle strength) and a functional enhancement that enables the patient to return to work . Bontoux et al. studied a population of 87 chronic LBP sufferers (mean age: 40.9; range: 18 to 53) with major problems at work and reported a significant improvement in pain intensity and physical test results at the end of the training programme and then six and 12 months afterwards. After four weeks of training, the latter authors also reported a significant decrease in the overall DPQ score (from 174.6 ± 73.3 to 91.9 ± 68.8 out of 400 for the absolute scores) and the four domain scores. There was also a significant improvement in the QBPDS score, which fell from 32 ± 5.1 to 18.8 ± 14.5 after four weeks . Verfaille et al. reported similar results for a sample of 26 chronic LBP patients (mean age: 44.7; range: 26 to 53) in terms of the VAS, SMRT, Shirado test and FFD. These authors also observed a significant improvement in the DPQ overall score and the four domain scores 11 months after the end of the treatment. In a population of 60 chronic LBP patients (mean age: 44 ± 9.8; range: 26 to 65), Genet et al. reported an improvement in all the physical parameters (except for the Sorensen test) at five weeks and at three months. In contrast, this improvement was no longer significant at 12 months, regardless of the physical parameter considered. The QBPDS score was significantly better at five weeks ( p = 0.007) but not at later time points. Lastly, Chaory et al. reported an improvement in pain and physical parameters (except for the SMRT) in a multicentre study of 70 chronic LBP patients (mean age: 42.5 ± 9.2). The authors also observed an improvement in the total QBPDS score (from 40.7 ± 15.7 to 28.1 ± 18.2) after a 5- or 6-week programme. The sensitivity to change (0.80 and 0.78 for the ES and the SRM, respectively) was similar to that found in the present work.

Our study confirmed these results on the clinical and functional levels. For the DPQ, we observed a significant improvement in the “daily living”, “work/leisure” and “anxiety/depression” domains. In contrast, we did not observe any change in the “social interest” domain. This difference may be related to the type of patient management used in the rehabilitation programme, which focuses essentially on the physical and functional domains of LBP and far less on the psychological domain. It can also be explained by the early evaluation (performed at the end of programme, after only four weeks), whereas the effects on the “social interest” domain become apparent later (as shown by Verfaille et al.’s observations after 11 months ). Likewise, Bontoux et al. showed that all the domains are improved after five weeks of a functional rehabilitation programme. In contrast, after six and 12 months, there was a drop off in the level of benefit provided by the programme for all domains. For the QBPDS score (which does not take into account psychosocial aspects), we observed significant improvements in all categories and in the overall score. These benefits were correlated with improvements in the physical tests (particularly the VAS).

Concerning the sensitivity to change, we noted a greater value for the QBPDS than for the DPQ when considering the SRM (0.80 and 0.59, respectively, for the overall score). In contrast, the QBPDS and DPQ’s sensitivities to change were similar when considering the ES (0.62 and 0.61, respectively). We also noted higher sensitivity for the QBPDS’s overall score, relative to its different categories. This can be explained by the overall score’s greater amplitude of variation (from 0 to 100), compared with that of the category scores (from 0 to 15 or 20). However, our results also show that each category was sensitive to change.

The difference in sensitivity between the two tools is probably related to their respective designs and the content of their items . In fact, the QBPDS only takes account of the patient’s functional limitations, whereas the DPQ evaluates cognitive and behavioural aspects and includes more subjective data (such as pain, anxiety/depression status and social relationships). However, in chronic LBP, the absence of a correlation between physical disability and the functional and psychological impact is well established . These various domains probably change over longer time scales and so the “social interest” domain is less likely to improve in just four weeks. Although the physical improvement prompted by the functional rehabilitation programme has a direct impact on physical and functional parameters, this is less true for psychosocial components which depend on other (notably environmental) factors.

1.5

Conclusion

This retrospective study of 30 LBP outpatients undergoing a 4-week functional rehabilitation programme showed that the QBPDS’s sensitivity to change (for the overall score and for the four constituent category scores) is satisfactory in this context and is greater than that of the DPQ. Indeed, the Dallas questionnaire appears to be less sensitive to change – notably for the “social interest” domain, although the latter may need to be evaluated further beyond the end of the functional rehabilitation programme.

Sensitivity to change influences a tool’s qualities and its suitability for particular purposes. However, the sensitivity evaluation must be designed according to the scale’s target population. In fact, we believe that the sensitivity of the QBPDS and the DPQ needs to be evaluated at different stages of acute, sub-acute and chronic LBP, in order to judge the impact of different treatments on the scales’ various domains.

2.1

Introduction

De nombreuses échelles d’incapacité fonctionnelle ont été développées dans le cadre de la lombalgie, particulièrement dans sa forme chronique . Les échelles d’Oswestry et de Québec, les questionnaires de Roland-Morris et de Dallas en sont les plus connus, mais aucun ne constitue l’outil gold standard , en regard notamment des critères métrologiques (fiabilité, validité, faisabilité, etc.) qui justifient le choix d’un outil de mesure.

Les deux outils les plus récents, le Quebec Back Pain Disability Scale (QBPDS), ou échelle de Québec , et le Dallas Pain Questionnaire (DPQ), ou questionnaire de Dallas , ont bénéficié d’études démontrant leur fiabilité et leur validité.

Le QBPDS, autoquestionnaire d’évaluation fonctionnelle spécifique de la lombalgie, a été développé et validé parallèlement en anglais et en français du Québec (Canada) par Kopec . Il prend en compte les limitations fonctionnelles liées à la douleur, dans le but de suivre l’évolution de sujets lombalgiques engagés dans des programmes de réadaptation. Cette échelle a fait la preuve de propriétés métrologiques satisfaisantes chez les lombalgiques : fiabilité, reproductibilité, validité de construit. Elle est considérée comme adaptée aux différents niveaux d’incapacité fonctionnelle. Elle est aussi d’une acceptabilité très satisfaisante et d’un temps de passation court (3 à 5 min) . Son utilisation en France est adaptée, malgré quelques termes plus habituels au français québécois . Sa sensibilité au changement, la validité prédictive des scores initiaux et son utilité dans les évaluations longitudinales restent cependant à préciser, notamment en langue française .

Le DPQ est un autoquestionnaire anglo-saxon basé sur une conception cognitivocomportementale de la douleur chronique et conçu pour évaluer le retentissement de la douleur lombaire dans la vie quotidienne . Son champ d’investigation dépasse l’incapacité physique pour s’intéresser aux activités sociales. Ses propriétés métrologiques (fiabilité, reproductibilité, validité de contenu, validité de construit, pouvoir discriminant, validité prédictive) sont établies chez des sujets lombalgiques chroniques . La version originale américaine n’a toutefois pas étudié la sensibilité au changement. Dans la version française du questionnaire de Dallas , la sensibilité au changement a été reconnue pour les dimensions « activités quotidiennes », « travail/loisirs » et « anxiété/dépression » mais pas pour la dimension « comportement social » .

Dans cette étude, nous proposons d’évaluer la sensibilité au changement de l’échelle de Québec et de la comparer à celle du questionnaire de Dallas, sur une population de sujets lombalgiques intégrés à un programme de restauration fonctionnelle du rachis.

2.2

Méthodologie

2.3

Résultats

2.3.2

Effet du programme de RFR

2.3.2.1

Indices physiques

Les résultats montrent une amélioration clinique significative pour l’ensemble des indices : EVA ( p = 0,0005), ISMR ( p = 0,001), Sorensen ( p < 0,0001), Shirado ( p = 0,003) et distance main sol ( p = 0,005) ( Tableau 1 ).

Tableau 1

Only gold members can continue reading. Log In or Register to continue

Share this:

• Click to share on Twitter (Opens in new window)
• Click to share on Facebook (Opens in new window)

Related

Related posts:

Les attentes des patients atteints de poliomyélite antérieure aiguë Post-polio syndrome: Pathophysiological hypotheses, diagnosis criteria, medication therapeutics The importance of fear, beliefs, catastrophizing and kinesiophobia in chronic low back pain rehabilitation The psychological aspects of polio survivors through their life experience Post-polio syndrome and rehabilitation Aging and sequelae of poliomyelitis

Stay updated, free articles. Join our Telegram channel

Join