Elsevier

Manual Therapy

Volume 20, Issue 1, February 2015, Pages 96-102
Manual Therapy

Original article
Prognostic factors and course for successful clinical outcome quality of life and patients' perceived effect after a cognitive behavior therapy for chronic non-specific low back pain: A 12-months prospective study

https://doi.org/10.1016/j.math.2014.07.003Get rights and content

Abstract

This study investigates the clinical course of and prognostic factors for quality of life (Short Form 36 items Health survey (SF-36)) and global perceived effect (GPE) in patients treated for chronic non-specific low back pain at 5 and 12-months follow-up. Data from a prospective cohort (n = 1760) of a rehabilitation center were used, where patients followed a 2-months cognitive behavior treatment. The outcome ‘improvement in quality of life (SF-36)’ was defined as a 10% increase in score on the SF-36 at follow-up compared with baseline. On the GPE scale, patients who indicated to be ‘much improved’ were coded as ‘clinically improved’. Multivariable logistic regression analysis included 23 baseline characteristics. At 5-months follow-up, scores on the SF-36 Mental Component Scale (SF-36; MCS) and the Physical Component Scale (SF-36; PCS) had increased from 46.6 (SD 10.3) to 50.4 (SD 9.8) and from 31.9 (SD 7.1) to 46.6 (SD 10.3), respectively. At 5-months follow-up, 53.0% of the patients reported clinical improvement (GPE) which increased to 60.3% at 12-months follow-up. The 10% improvement in quality of life (SF-36 MCS) at 5-months follow-up was associated with patient characteristics and psychological factors. At 5-months follow-up, the 10% improvement in quality of life (SF-36 PCS) and GPE was associated with patient characteristics, physical examination, work-related factors and psychological factors; for GPE, an association was also found with clinical status. At 12-months follow-up GPE was associated with patient characteristics, clinical status, physical examination and work-related factors. The next phase in this prognostic research is external validation of these results.

Introduction

Chronic non-specific low back pain (CNSLBP) is one of the most prevalent health problems (Heneweer et al., 2007). Although it is known that physical, psychosocial and personal factors play a role, the way they interact with each other remains unclear. Several prognostic models for non-specific low back pain have been described; however, the prognostic factors varied depending on the choice of, for example, the prognostic variables, outcome definition, or the stage of pain (e.g. acute, sub-acute or chronic) (Kent and Keating, 2008, Costa Lda et al., 2009, Verkerk et al., 2012). A recent systematic review focusing on musculoskeletal complaints considered relevant for physical therapists in primary care, reported that the available prediction models are not yet ready to be applied in clinical practice because of their preliminary stage of development (van Oort et al., 2012). Also, the available models for back pain patients need external validation and impact evaluation before applying them in daily practice (van Oort et al., 2012). Compared to patients with (sub) acute NSLBP, patients with CNSLBP are the least investigated regarding their course and prognosis, especially in relation to the outcomes ‘quality of life’ and ‘global perceived effect’ (GPE) (Verkerk et al., 2012). Therefore, clinicians and researchers increasingly recognize the importance of such patient-reported outcome measures in the evaluation of the effectiveness of treatment, prognosis or course of CNSLBP (Bombardier, 2000).

Achieving and maintaining the best possible quality of life is a primary goal of care and several questionnaires are available to measure this item, including the Short Form 36-items Health Survey (SF-36) (Aktekin et al., 2009). With regard to evaluating GPE, the patient can be asked to rate how much their condition (i.e. important aspects of recovery) has improved or deteriorated since some predefined time point (Kamper et al., 2010). The present study was designed to investigate the course of and identify prognostic factors (with internal validation) for quality of life and GPE in patients treated for CNSLBP.

Section snippets

Population

Patients were recruited between January 2003 and December 2008 in a prospective cohort study from a multidisciplinary outpatient rehabilitation clinic the Spine & Joint Centre (SJC; Rotterdam, The Netherlands). The Medical Ethics Committee of SJC approved the study protocol and all patients provided informed consent. Details on the study design are described elsewhere (Verkerk et al., 2011). Inclusion criteria were: 1) men and women aged ≥18 years; 2) having CNSLBP defined as a duration of LBP

Population

A total of 1760 patients [mean age 40.1 (10.6) years; 74.3% women] with CNSLBP participated in the study. Of these 1760 patients, 1696 (96.4%) completed the 2-month multidisciplinary treatment, 1564 (88.9%) participated in the 5-month follow-up, and 965 (54.8%) completed the 12-month follow-up after start of therapy. Table 1 presents the baseline characteristics of the 1760 patients and the distribution of the possible prognostic factors (Verkerk et al., 2011).

Course at 2 and 5 months

At 2 and 5-months follow-up the

Discussion

In the present study, a main finding is the sustained 10% improvement on the PCS (76.3% of the population) up to 5 months and on GPE (60.3%) up to 12 months. For MCS this 10% improvement is slightly less (20.6%) at 5 months, but a mean of 50 (SD of 10) represents normal health and function (Walsh et al., 2003). Some patients reported no improvement on GPE at 5 and 12-months follow-up (15% and 20.6%, respectively).

The present study shows that improvement in quality of life (on SF-36 MCS) at

Acknowledgment

The study was financial supported by Rotterdam University of Applied Sciences and Department of General Practice, Erasmus MC. The authors declare no conflict of interest.

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