Prognostic factors for perceived pain and function at one-year follow-up in primary care patients with neck pain

Purpose: To identify prognostic factors for perceived pain and function with focus at one-year follow-up in primary care patients treated for non-specific neck pain. Methods: A prospective study was performed including 193 neck pain patients. Before and after treatment period, and 12 months after the start date for treatment, patients completed a questionnaire including background data and aspects of pain, function and general health. Linear multiple regression analysis was used to identify prognostic factors with the dependent variables Oswestry score and pain intensity at 12-month follow-up. Response rate 81%. Results: At 12-month follow-up, Oswestry score identified four prognostic factors: pain intensity; well-being; expectations of treatment; and duration of current episode. Adjusted R² for the model was 0.32, and 20% of the patients had three of the four prognostic factors at entry, indicating risk of poor outcome. The dependent variable pain intensity revealed three prognostic factors: Oswestry score; duration of current episode; and similar problem during the previous five years. Adjusted R² was 0.24, and 60% of the patients had two of the three prognostic factors at entry, indicating risk of poor outcome. Conclusions: Different prognostic factors (with the exception of duration of current episode) were identified by the two outcome variables. Thus the results suggest that it should be taken into account whether an impairment or disability outcome is used.     

Prognostic factors for perceived pain and function at one-year follow-up in primary care patients with neck pain

Purpose: To identify prognostic factors for perceived pain and function with focus at one-year follow-up in primary care patients treated for non-specific neck pain. Methods: A prospective study was performed including 193 neck pain patients. Before and after treatment period, and 12 months after the start date for treatment, patients completed a questionnaire including background data and aspects of pain, function and general health. Linear multiple regression analysis was used to identify prognostic factors with the dependent variables Oswestry score and pain intensity at 12-month follow-up. Response rate 81%. Results: At 12-month follow-up, Oswestry score identified four prognostic factors: pain intensity; well-being; expectations of treatment; and duration of current episode. Adjusted R² for the model was 0.32, and 20% of the patients had three of the four prognostic factors at entry, indicating risk of poor outcome. The dependent variable pain intensity revealed three prognostic factors: Oswestry score; duration of current episode; and similar problem during the previous five years. Adjusted R² was 0.24, and 60% of the patients had two of the three prognostic factors at entry, indicating risk of poor outcome. Conclusions: Different prognostic factors (with the exception of duration of current episode) were identified by the two outcome variables. Thus the results suggest that it should be taken into account whether an impairment or disability outcome is used.     

Course and prognostic factors of whiplash: a systematic review and meta-analysis

We conducted a systematic review and meta-analysis of prospective cohort studies of subjects with acute whiplash injuries. The aim was to describe the course of recovery, pain and disability symptoms and also to assess the influence of different prognostic factors on outcome. Studies were selected for inclusion if they enrolled subjects with neck pain within six weeks of a car accident and measured pain and/or disability outcomes. Studies were located via a sensitive search of electronic databases; Medline, Embase, CINAHL, Cochrane database, ACP Journal club, DARE and Psychinfo and through hand-searches of relevant previous reviews. Methodological quality of all studies was assessed using a six item checklist. Sixty-seven articles, describing 38 separate cohorts were included. Recovery rates were extremely variable across studies but homogeneity was improved when only data from studies of more robust methodological quality were considered. These data suggest that recovery occurs for a substantial proportion of subjects in the initial 3 months after the accident but after this time recovery rates level off. Pain and disability symptoms also reduce rapidly in the initial months after the accident but show little improvement after 3 months have elapsed. Data regarding the prognostic factors associated with poor recovery were difficult to interpret due to heterogeneity of the techniques used to assess such associations and the way in which they are reported. There was also wide variation in the measurement of outcome and the use of validated measures would improve interpretability and comparability of future studies.     

Prognostic factors for neck pain in general practice

Prognostic studies on neck pain are scarce and are typically restricted to short-term follow-up only. In this prospective cohort study, indicators of short- and long-term outcomes of neck pain were identified that can easily be measured in general practice. Patients between 18 and 70 years of age, suffering for at least 2 weeks from neck pain were recruited by 42 general practitioners (GPs). Perceived recovery, pain intensity and neck dysfunction after 7 and 52 weeks were considered as outcome measures. Indicators of prognosis were identified by means of logistic regression analyses (perceived recovery) and linear regression analyses (pain intensity and neck dysfunction). In total, 183 patients were included. After 1 year, 63% had recovered. The prognostic models showed differences between short- and long-term indicators. At the short term, besides the baseline values of the respective outcome measurements, only older age (≥40) and concomitant low back pain and headache were associated with poor outcome. At the long term, in addition to age and concomitant low back pain, previous trauma, a long duration of neck pain, stable neck pain during the 2 weeks prior to baseline measurement, and previous neck pain predicted poor prognosis. The predictive power of the models was weak: the explained variance (R²) varied from 24 to 36%. Patient history and physical examination give GPs little handholds to predict the prognosis for patients with sub-acute and chronic neck pain. A few indicators of a less favourable prognosis of neck pain were identified, of which older age and concomitant low back pain was the most consistent.     

Acute low back pain: clinical course and prognostic factors

Purpose.?The aim of this study was to assess the clinical course of patients with acute low back pain (LBP) throughout 12 weeks and to identify the prognostic factors for non-recovery in the short term.

Method.?A total of 91 patients with acute LBP (<3 weeks) were included in this study. Baseline assessments including demographic variables, clinical characteristics of pain, lost work time and results of clinical examination were noted. Pain intensity, disability, general health perception and depression were assessed according to visual analogue scale, Roland Morris Disability Questionnaire (RMDQ), Nottingham Health Profile (NHP) and Beck Depression Inventory, respectively. Patients were assessed for pain intensity and disability at baseline, and at 1, 2, 4, 8 and 12 weeks of follow-up. Recovery was considered if patients scored <4 on the RMDQ and pain had resolved. At the 2nd week of follow-up, patients were divided into two groups according to recovery (Group 1) or non-recovery (Group 2) to identify the prognostic factors, which were analysed by multiple logistic regression.

Results.?At 2 weeks, 52 (57.1%) of the patients had recovered and only eight (8.7%) developed chronic LBP. Mean pain intensity and mean disability scores dropped 96.7 and 96.4%, respectively, of initial levels during the 12 weeks. Sixty per cent of 63 employed patients reported lost time from work. A comparison between groups revealed that finger-floor distance, RMDQ and NHP (pain, physical mobility, emotional reactions, sleep, energy level, and distress subgroups) were statistically significantly lower in Group 1, and NHP-pain was strongly associated with non-recovery in the short term.

Conclusions.?Acute LBP patients with disability generally recover in the first weeks. General health perception (NHP) – pain subgroup score was identified in particular as the best prognostic factor for non-recovery in the short term. Hence, pain should be given particular consideration in baseline assessments of acute LBP patients.     

Post-trauma ratings of pre-collision pain and psychological distress predict poor outcome following acute whiplash trauma: a 12-month follow-up study

Patients with acute whiplash trauma were followed to examine if post-trauma ratings of pre-collision pain and psychological distress were associated with reduced work capability and neck pain at 12 months follow-up. The study included 740 consecutive patients (474 females, 266 males) referred from emergency departments or primary care after car accidents in four counties in Denmark. After the collision patients received a questionnaire on psychological distress, unspecified pain and socio-demographics and 12 months later a follow-up on work capability and neck pain was performed. Risk factors were identified by multiple logistic regression analysis. Factors associated with affected work capacity at the 12-month follow-up were pre-collision unspecified pain condition (OR=2.4, p=0.002) and socio-demographic characteristics: female gender, low educational level, unemployment and blue collar worker. Factors associated with considerable neck pain at follow-up were pre-collision unspecified pain (OR=3.5, p<0.000), pre-collision high psychological distress (OR=2.1, p=0.03) and socio-demographic characteristics: female gender and formal education >4 years. Pre-collision neck pain and severity of accident were not associated with poor outcome. In conclusion unspecified as opposed to specified pain (neck pain) before the collision is associated with poor recovery and high accumulation of pre-collision psychological distress is associated with considerable neck pain at follow-up. However, no conclusions on causality can be drawn. Personal characteristics before the collision are important for recovery and attention to pre-collision characteristics may contribute to the prevention of poor recovery after acute whiplash trauma.     

Continued disability and pain after lumbar disc surgery: the role of cognitive-behavioral factors

Cognitive-behavioral factors are considered important in the development of chronic disability and pain in patients with low back pain. In a prospective cohort study of 277 patients undergoing surgery for lumbosacral radicular syndrome, the predictive value of preoperatively measured cognitive-behavioral factors (fear of movement/(re)injury, passive pain coping, and negative outcome expectancies) for disability and pain intensity at 6 weeks and 6 months after surgery was investigated, taking into account the effect of possible confounding variables. Higher levels of cognitive-behavioral factors were found to be associated with a worse outcome at both 6 weeks and 6 months. These associations remained significant after controlling for possible confounding variables (preoperative disability and pain intensity, age, gender, educational level, duration of complaints, neurological deficits, and intake of analgesics) and pain intensity 3 days postoperatively. In multiple regression analyses, the cognitive-behavioral factors independently predicted different outcomes. Fear of movement/(re)injury predicted more disability and more severe pain at 6 weeks and more severe pain at 6 months; passive pain-coping strategies predicted more disability at 6 months; and negative outcome expectancies predicted more disability and more severe pain at both 6 weeks and 6 months. The findings support the potential utility of preoperative screening measures that include cognitive-behavioral factors for predicting surgical outcome, as well as studies to examine the potential benefits of cognitive-behavioral treatment to improve surgical outcome.     

External validation of prognostic models for recovery in patients with neck pain

BackgroundNeck pain is one of the leading causes of disability in most countries and it is likely to increase further. Numerous prognostic models for people with neck pain have been developed, few have been validated. In a recent systematic review, external validation of three promising models was advised before they can be used in clinical practice.ObjectiveThe purpose of this study was to externally validate three promising models that predict neck pain recovery in primary care.MethodsThis validation cohort consisted of 1311 patients with neck pain of any duration who were prospectively recruited and treated by 345 manual therapists in the Netherlands. Outcome measures were disability (Neck Disability Index) and recovery (Global Perceived Effect Scale) post-treatment and at 1-year follow-up. The assessed models were an Australian Whiplash-Associated Disorders (WAD) model (Amodel), a multicenter WAD model (Mmodel), and a Dutch non-specific neck pain model (Dmodel). Models’ discrimination and calibration were evaluated.ResultsThe Dmodel and Amodel discriminative performance (AUC < 0.70) and calibration measures (slope largely different from 1) were poor. The Mmodel could not be evaluated since several variables nor their proxies were available.ConclusionsExternal validation of promising prognostic models for neck pain recovery was not successful and their clinical use cannot be recommended. We advise clinicians to underpin their current clinical reasoning process with evidence-based individual prognostic factors for recovery. Further research on finding new prognostic factors and developing and validating models with up-to-date methodology is needed for recovery in patients with neck pain in primary care.     

Factors predicting clinical outcome 12 and 36 months after an exercise intervention for recurrent low-back pain

Purpose: The aim of this cohort study was to identify early predictive factors for a poor outcome of disability and pain 12- and 36-months after an intervention in patients with recurrent low-back pain, currently at work. Method: Seventy-one patients with recurrent low-back pain, all at work, seeking care in a primary health care setting were included. Predictive indicators including demographic data and health-related variables were derived from questionnaires pre- and post intervention over eight weeks. The dependent outcome variables were perceived disability and present pain at 12- and 36-months. Results: Multivariate regression analyses show that early data on poor self-efficacy for physical activity, greater disability, and higher level of pain-ratings emerged as independent predictors of a poor outcome of disability at 12 and 36 months. Higher ratings of pain and poor self-efficacy appeared again as independent predictors of a poor outcome of pain at the 12-month follow-up. Pain frequency ratings predicted a poor outcome of pain at 36 months. Conclusions: Our results suggest that ratings of poor self-efficacy for physical activity, greater disability, and pain-ratings, are the most consistent independent predictors of long-term poor outcome of disability and pain. This indicates the importance of screening for such factors to optimize the management of low-back pain. However, larger studies in similar patient populations are needed to confirm these results.

Implications for Rehabilitation

• Patients ratings of self-efficacy for physical activities, disability and pain predict long-term poor outcome of perceived disability and pain in subjects with recurrent low-back pain.

• Prognostic information about self-efficacy for physical activity may be used to tailor intervention to prevent future disablement resulting from further episodes of recurrent low-back pain.

• It is important to implement knowledge of predictive factors in the clinical work.

     

Do whiplash patients differ from other patients with non-specific neck pain regarding pain, function or prognosis?

We evaluated whether patients with self-reported whiplash differed in perceived pain, functional limitation and prognosis from patients with other painful neck complaints.Data from three Dutch trials and an English trial were used all evaluating conservative treatment in neck pain patients in primary care. All patients had non-specific neck pain. Information on any trauma or injury came from self-report at baseline. We compared frequencies of baseline variables and outcome at short-term and long term for whiplash and non-trauma neck pain patients separately.The total study population consisted of 804 neck pain patients. Of these patients 133 reported (16.5%) that an injury was the cause of their neck pain. In all trials there were 17–18% more male patients in the whiplash group. At follow-up pain decreased between 12 and 28%, function 10%, and 25–50% of patients recovered in all trials. Post-treatment improvements in pain, function and recovery were comparable between whiplash and non-trauma patients. We also found no different prognostic factors between whiplash and non-trauma patients.Overall we found in a population with mild to moderate pain no clinically relevant differences between patients with self-reported whiplash and patients with other painful neck complaints. The findings suggest that whiplash patients with mild to moderate pain should not be considered a specific subgroup of patients with non-specific neck pain.     

Residual complaints following lumbar disc surgery: prognostic indicators of outcome

Physical as well as psychological features might be important prognostic factors for residual complaints following lumbar disc surgery in primary care. No studies have yet investigated both factors simultaneously. The aim of this prospective cohort study was to identify indicators of the short and long-term outcome of residual complaints following lumbar disc surgery. Patients (n=105), aged between 18 and 65 years, were included if they still suffered residual complaints 6 weeks after first-time lumbar disc surgery and had therefore been referred to physiotherapy. All potential indicators were measured at baseline except treatment expectancy, which was measured after two treatment sessions enabling patients to rate treatment expectancy based on their actual perception of the treatment. Dimensions of recovery included perceived recovery, functional status, and pain intensity (back and leg) at the 3-month and 12-month follow-up. It was found that high treatment expectancy was associated with a favorable outcome on perceived recovery and functional status, both at the 3 and the 12-month follow-up. Taking pain medication and a poor functional status at baseline were associated with poor perceived recovery and functional status at both follow-up measurements. Leg pain and back pain at baseline were associated with residual leg and back pain at the 3 and the 12-month follow-up, respectively. The results for perceived recovery and functional status were rather robust. However, for leg pain and back pain, the results were less stable. Apparently, the clinical course to recovery of residual leg pain and residual back pain is not strongly influenced by these indicators.     

The Long-Term Prognosis in People With Recent Onset Low Back Pain From Emergency Departments: An Inception Cohort Study

Most studies investigating the course of recent-onset low back pain (LBP) included patients from primary care. We aimed to describe the prognosis in people with recent-onset LBP presenting to emergency departments (EDs) and to identify prognostic factors for nonrecovery. This inception cohort study with a 1-year follow-up recruited 600 consecutive acute LBP patients presenting to 4 EDs. The outcomes measured the days to recover from pain, recover from disability, return to previous work hours and duties, and complete recovery. Within 12 months, 73% of participants (95% confidence interval [CI] = 69–77) recovered from pain, 86% (95% CI = 82–90) recovered from disability, 79% (95% CI = 71–87) returned to previous work hours and duties, and 70% (95% CI = 66–74) completely recovered. The median recovery times were 67 days (95% CI = 54–80) to recover from pain, 37 days (95% CI = 31–43) to recover from disability, 37 days (95% CI = 25–49) to return to previous work hours and duties, and 70 days (95% CI = 57–83) to recover completely. Higher pain levels, a higher perceived risk of persistent LBP, more days of reduced activity due to LBP, more pain sites, and higher duration of LBP were associated with complete nonrecovery within 6 months.PerspectiveThis information relates to prognosis and to likely recovery times for patients with recent-onset LBP in EDs. The findings also confirm previous factors associated with poor outcomes in patients with recent-onset LBP.     

Prognostic factors of whiplash-associated disorders: a systematic review of prospective cohort studies

We present a systematic review of prospective cohort studies. Our aim was to assess prognostic factors associated with functional recovery of patients with whiplash injuries. The failure of some patients to recover following whiplash injury has been linked to a number of prognostic factors. However, there is some inconsistency in the literature and there have been no systematic attempts to analyze the level of evidence for prognostic factors in whiplash recovery. Studies were selected for inclusion following a comprehensive search of MEDLINE, EMBASE, CINAHL, the database of the Dutch Institute of Allied Health Professions up until April 2002 and hand searches of the reference lists of retrieved articles. Studies were selected if the objective was to assess prognostic factors associated with recovery; the design was a prospective cohort study; the study population included at least an identifiable subgroup of patients suffering from a whiplash injury; and the paper was a full report published in English, German, French or Dutch. The methodological quality was independently assessed by two reviewers. A study was considered to be of 'high quality' if it satisfied at least 50% of the maximum available quality score. Two independent reviewers extracted data and the association between prognostic factors and functional recovery was calculated in terms of risk estimates. Fifty papers reporting on twenty-nine cohorts were included in the review. Twelve cohorts were considered to be of 'high quality'. Because of the heterogeneity of patient selection, type of prognostic factors and outcome measures, no statistical pooling was able to be performed. Strong evidence was found for high initial pain intensity being an adverse prognostic factor. There was strong evidence that for older age, female gender, high acute psychological response, angular deformity of the neck, rear-end collision, and compensation not being associated with an adverse prognosis. Several physical (e.g. restricted range of motion, high number of complaints), psychosocial (previous psychological problems), neuropsychosocial factors (nervousness), crash related (e.g. accident on highway) and treatment related factors (need to resume physiotherapy) showed limited prognostic value for functional recovery. High initial pain intensity is an important predictor for delayed functional recovery for patients with whiplash injury. Often mentioned factors like age, gender and compensation do not seem to be of prognostic value. Scientific information about prognostic factors can guide physicians or other care providers to direct treatment and to probably prevent chronicity.     

Prognostic factors in first-time care seekers due to acute low back pain.

There is limited knowledge on prognostic factors for developing chronic low back pain (LBP) at an early stage of LBP. The objectives of this study were to investigate the clinical course of pain and disability, and prognostic factors for non-recovery after 1-year, in patients seeking help for the first time due to acute LBP. An inception cohort study included 123 patients with acute LBP lasting less than 3 weeks and consulting primary care for the first time. Main outcome measures were pain intensity, Roland-Morris disability questionnaire (RMQ), and sickness absence. Eleven patients (9%) did not return for the 12-month follow-up. There were large and significant reductions in pain intensity (P<0.001) and RMQ scores (P<0.001) during follow-up. Patients with neurological signs showed significantly less improvement in pain (P=0.001) and RMQ (P=0.004) compared with those without neurological signs. The proportions with sickness absence due to LBP at 6, 9, and 12 months were 7%, 8%, and 9%, respectively. At 12 months, 17% of patients had not fully recovered. Multivariate logistic regression analyses showed that high scores on a psychosocial screening (acute low back pain screening questionnaire) and emotional distress (Hopkin's symptom check list) were significantly associated with non-recovery at 12 months, with odds ratios of 4.4 (95% confidence interval 1.1-17.4) and 3.3 (1.1-10.2), respectively.     

Derivation of a clinical prediction rule to identify both chronic moderate/severe disability and full recovery following whiplash injury

Recovery following a whiplash injury is varied: approximately 50% of individuals fully recover, 25% develop persistent moderate/severe pain and disability, and 25% experience milder levels of disability. Identification of individuals likely to develop moderate/severe disability or to fully recover may help direct therapeutic resources and optimise treatment. A clinical prediction rule (CPR) is a research-generated tool used to predict outcomes such as likelihood of developing moderate/severe disability or experiencing full recovery from whiplash injury. The purpose of this study was to assess the plausibility of developing a CPR. Participants from 2 prospective, longitudinal studies that examined prognostic factors for poor functional recovery following whiplash injury were used to derive this tool. Eight factors, previously identified as predictor variables of poor recovery, were included in the analyses: initial neck disability index (NDI), initial neck pain (visual analogue scale), cold pain threshold, range of neck movement, age, gender, presence of headache, and posttraumatic stress symptoms (Posttraumatic Diagnostic Scale [PDS]). An increased probability of developing chronic moderate/severe disability was predicted in the presence of older age and initially higher levels of NDI and hyperarousal symptoms (PDS) (positive predictive value [PPV] = 71%). The probability of full recovery was increased in younger individuals with initially lower levels of neck disability (PPV = 71%). This study provides initial evidence for a CPR to predict both chronic moderate/severe disability and full recovery following a whiplash injury. Further research is needed to validate the tool, determine the acceptability of the proposed CPR by practitioners, and assess the impact of inclusion in practice.     

Acute stress response and recovery after whiplash injuries. A one‐year prospective study

Chronic whiplash‐associated disorder (WAD) represents a major medical and psycho‐social problem. The typical symptomatology presented in WAD is to some extent similar to symptoms of post traumatic stress disorder. In this study we examined if the acute stress reaction following a whiplash injury predicted long‐term sequelae. Participants with acute whiplash‐associated symptoms after a motor vehicle accident were recruited from emergency units and general practitioners. The predictor variable was the sum score of the impact of event scale (IES) completed within 10 days after the accident. The main outcome‐measures were neck pain and headache, neck disability, general health, and working ability one year after the accident. A total of 737 participants were included and completed the IES, and 668 (91%) participated in the 1‐year follow‐up. A baseline IES‐score denoting a moderate to severe stress response was obtained by 13% of the participants. This was associated with increased risk of considerable persistent pain (OR=3.3; 1.8–5.9), neck disability (OR=3.2; 1.7–6.0), reduced working ability (OR=2.8; 1.6–4.9), and lowered self‐reported general health one year after the accident. These associations were modified by baseline neck pain intensity. It was not possible to distinguish between participants who recovered and those who did not by means of the IES (AUC=0.6). In conclusion, the association between the acute stress reaction and persistent WAD suggests that post traumatic stress reaction may be important to consider in the early management of whiplash injury. However, the emotional response did not predict chronicity in individuals.     

The effect of fear of movement on muscle activation in posttraumatic neck pain disability

Studies using surface electromyography have demonstrated a reorganization of muscle activation patterns of the neck and shoulder muscles in patients with posttraumatic neck pain disability. The neurophysiologically oriented "pain adaptation" model explains this reorganization as a useful adaptation to prevent further pain and injury. The cognitive-behavioral-oriented "fear avoidance" model suggests that fear of movement, in addition to the effects of pain, modulates the muscle activation level. We analyzed the extent to which pain and fear of movement influenced the activation patterns of the upper trapezius muscle during the transition from acute to chronic posttraumatic neck pain. Ninety-two people with an acute traumatic neck injury after a motor vehicle accident were followed up for 24 weeks. Visual analog scale ratings of pain intensity, response on the Tampa Scale of Kinesophobia--fear of movement, and surface electromyography of the upper trapezius muscles during a submaximal isometric physical task were obtained at 1, 4, 8, 12, and 24 weeks after the motor vehicle accident. Multilevel analysis revealed that an increased level of both fear of movement (t value=-2.19, P=0.030) and pain intensity (t value=-2.94, P=0.004) were independently associated with a decreased level of muscle activation. Moreover, the results suggest that the association between fear of movement and lower muscle activity level is stronger in patients reporting high pain intensity (t value=2.15, P=0.033). The contribution of pain intensity to the muscle activation level appeared to decrease over time after the trauma (t value=2.58, P=0.011). The results support both the "pain adaptation" and the "fear avoidance" models. It is likely that the decrease in muscle activation level is aimed at "avoiding" the use of painful muscles.     

Contributions of prognostic factors for poor outcome in primary care low back pain patients

Background: Back pain is common and some sufferers consult GPs, yet many sufferers develop persistent problems. Combining information on risk of persistence and prognostic indicator prevalence provides more information on potential intervention targets than risk estimates alone. Aims: To determine the proportion of primary care back pain patients with persistent problems whose outcome is related to measurable prognostic factors. Methods: Prospective cohort study of back pain patients (30–59 years) at five general practices in Staffordshire, UK (n =389). Baseline factors (demographic; episode duration; symptom severity; pain widespreadness; anxiety; depression; catastrophising; fear‐avoidance; self‐rated health) were assessed for their association with disabling and limiting pain after 12‐months. The proportion of those with persistent problems whose outcome was related to each factor was calculated. Results: Prevalence of prognostic factors ranged from 23% to 87%. Strongest predictors were unemployment (adjusted relative risk (RR) 4.2; 95% CI 2.0, 8.5) and high pain intensity (4.1; 1.7, 9.9). The largest proportions of persistent problems were related to high pain intensity (68%; 95% CI 27, 87%) and unemployment (64%; 33, 82%). Combining these indicated that 85% of poor back pain outcome is related to these two factors. Poor self‐rated health, functional disability, upper body pain and pain bothersomeness were related with outcome for over 40% of those with persistent problems. Conclusions: Several factors increased risk of poor outcome in back pain patients, notably high pain and unemployment. These risks in combination with high prevalence of risk factors in this population distinguish factors that can help identify targets or sub‐groups for intervention.     

Systematic review of prognostic cohort studies on shoulder disorders

Shoulder complaints are common and have an unfavourable outcome in many patients. Only 50% of all new episodes of shoulder disorders end in complete recovery within 6 months. There is no consensus about prognostic indicators that can identify patients at high and low risk of chronicity. By a systematic search of the literature we identified 16 studies focusing on the prognosis of shoulder disorders. The methodological quality of these 16 studies was assessed. Six of these were considered to be of relatively 'high quality'. There was a wide variety among the studies in length of follow-up, study population, evaluated prognostic factors, type of outcome measure and method of analysis. Due to this large heterogeneity, we refrained from statistical pooling. Instead, we used a best-evidence synthesis. There is strong evidence that high pain intensity predicts a poorer outcome in primary care populations and that middle age (45-54) is associated with poor outcome in occupational populations. There is moderate evidence that a long duration of complaints, and high disability score at baseline predict a poorer outcome in primary care. These results need to be interpreted with caution because of the small number of studies on which these conclusions are based, and the large heterogeneity among studies regarding follow-up, outcome measures, and analysis.     

Does fear of movement mediate the relationship between pain intensity and disability in patients following whiplash injury? A prospective longitudinal study

The aim of this study was to test the capacity of the Fear Avoidance Model to explain the relationship between pain and disability in patients with whiplash-associated disorders. Using the method of Baron and Kenny [1], we assessed the mediating effect of fear of movement on the cross-sectional and longitudinal relationships between pain and disability. Two hundred and five subjects with neck pain due to a motor vehicle accident provided pain intensity (0 to 10 numerical rating scale), fear of movement (Tampa Scale of Kinesiophobia and Pictorial Fear of Activity Scale) and disability (Neck Disability Index) scores within 4 weeks of their accident, after 3 months, and after 6 months. The analyses were consistent with the Fear Avoidance Model mediating approximately 20% to 40% of the relationship between pain and disability. Contrary to our initial hypothesis, the proportion of the total effect of pain on disability that was mediated by fear of movement did not substantially change as increasing time elapsed after the accident. The proportion mediated was slightly higher when fear of movement was measured by Tampa Scale of Kinesiophobia as compared with Pictorial Fear of Activity Scale. The findings of this study suggest that the Fear Avoidance Model plays a role in explaining a moderate proportion of the relationship between pain and disability after whiplash injury.