Jeanine A. Verbunt

Disuse and deconditioning in chronic low back pain: Concepts and hypotheses on contributing mechanisms

For years enhancement of a patients level of physical fitness has been an important goal in rehabilitation treatment in chronic low back pain (CLBP), based on the hypothesis that physical deconditioning contributes to the chronicity of low back pain. However, whether this hypothesis in CLBP holds is not clear. In this paper, possible mechanisms that contribute to the development of physical deconditioning in CLBP, such as avoidance behaviour and suppressive behaviour, are discussed. The presence of both deconditioning‐related physiological changes, such as muscle atrophy, changes in metabolism, osteoporosis and obesity as well as deconditioning related functional changes, such as a decrease in cardiovascular capacity, a decrease in muscle strength and impaired motor control in patients with CLBP are discussed. Results of studies on the level of physical activities in daily life (PAL) and the level of physical fitness in patients with CLBP compared to healthy controls were reviewed. In studies on PAL results that were either lower or comparable to healthy subjects were found. The presence of disuse (i.e., a decrease in the level of physical activities in daily life) in patients with CLBP was not confirmed. The inconclusive findings in the papers reviewed may partly be explained by different measurement methods used in research on PAL in chronic pain. The level of physical fitness of CLBP patients also appeared to be lower or comparable to the fitness level of healthy persons. A discriminating factor between fit and unfit patients with back pain may be the fact that fit persons more frequently are still employed, and as such may be involved more in physical activity. Lastly some suggestions are made for further research in the field of disuse and deconditioning in CLBP.

Cognitive impairments in survivors of out-of-hospital cardiac arrest: A systematic review

OBJECTIVE To describe the current evidence on the frequency and nature of cognitive impairments in survivors of out-of-hospital cardiac arrest. DESIGN Systematic review. DATA SOURCES Pubmed, Embase, PsychInfo and Cinahl (1980-2006). No language restriction was imposed. REVIEW METHODS The following inclusion criteria were used: participants had to be survivors of out-of-hospital cardiac arrest, 18 years or older, and there had to be least one cognitive outcome measure with a follow-up of 3 months or more. Case reports and qualitative studies were excluded. The articles were screened on title, abstract and full text by two reviewers. All selected articles were reviewed and assessed by two reviewers independently using a quality criteria list. RESULTS Out of the 286 articles initially identified, 28 were selected for final evaluation. There was a high heterogeneity between the studies with regard to study design, number of participants, outcome measures and duration of follow-up. In general, the quality of the articles appeared low, with a few positive exceptions. The reported frequency of cognitive impairments in survivors of out-of-hospital cardiac arrest ranged from 6% to 100%. Memory problems were the most common cognitive impairment, followed by impairments in attention and executive functioning. Three high-quality prospective studies found that cognitive problems occurred in about half of the survivors of out-of-hospital cardiac arrest. CONCLUSION There are few good studies on the frequency of cognitive impairments after out-of-hospital cardiac arrest. However, cognitive problems, in particular memory problems, seem common in survivors of out-of-hospital cardiac arrest.

Life after survival: Long-term daily functioning and quality of life after an out-of-hospital cardiac arrest

BACKGROUND Information about long-term consequences of cardiac arrest is sparse. Because the survival rate is expected to increase, better knowledge of long-term functioning and quality of survival is essential. OBJECTIVES To determine the level of functioning of out-of-hospital cardiac arrest survivors 1-6 years later, and to evaluate the predictive value of medical variables on long-term functioning. METHODS A retrospective cohort study including 63 survivors of an out-of-hospital cardiac arrest, admitted to a Dutch University hospital between 2001 and 2006. Participants received a questionnaire by post. Primary outcome measures were: participation in society (Community Integration Questionnaire) and quality of life (SF-36). Secondary outcome measures were: physical, cognitive and emotional impairment, daily functioning and caregiver strain. Statistical analyses included multiple regression analyses. RESULTS On average 3 years post-cardiac arrest, 74% of the patients experienced a low participation level in society compared with the general population. Over 50% reported severe fatigue, 38% feelings of anxiety and/or depression and 24% a decreased quality of life. Caregivers reported stress related responses, feelings of anxiety and lower quality of life. Seventeen percent of the caregivers reported high caregiver strain, which was associated with the patients level of functioning. Gender, age, percutaneous coronary intervention (PCI) and therapeutic hypothermia contributed to outcome on at least one domain of long-term functioning. CONCLUSIONS After surviving an out-of-hospital cardiac arrest, many patients and partners encounter extensive impairments in their level of functioning and quality of life. Gender, age, PCI and therapeutic hypothermia are associated with differences in long-term functioning of patients.

Disuse and physical deconditioning in the first year after the onset of back pain

Abstract For years, physical deconditioning has been thought to be both a cause and a result of back pain. As a consequence physical reconditioning has been proposed as treatment‐goal in patients with chronic low back pain (LBP). However, it is still unclear whether a patient’s physical fitness level really decreases after pain‐onset. The objectives of the present study were, firstly, to test the assumption that long‐term non‐specific LBP leads to a decrease of the level of physical activity (disuse), secondly, to evaluate any development of physical deconditioning as a result of disuse in CLBP, and thirdly, to evaluate predictors for disuse in CLBP. A longitudinal cohort study over one year including 124 patients with sub‐acute LBP (i.e., 4–7 weeks after pain onset) was performed. Main outcome measures were change in physical activity level (PAL) and physical fitness (measured by changes in body weight, body fat and muscle strength) over one year. Hypothesized predictors for disuse were: pain catastrophizing; fear of movement; depression; physical activity decline; the perceived level of disability and PAL prior to pain. Results showed that only in a subgroup of patients a PAL‐decrease had occurred after the onset of pain, whereas no signs of physical deconditioning were found. Negative affect and the patients’ perceived physical activity decline in the subacute phase predicted a decreased level of PAL over one year. Based on these results, we conclude that as to the assumption that patients with CLBP suffer from disuse and physical deconditioning empirical evidence is still lacking.

Fear of injury and physical deconditioning in patients with chronic low back pain

OBJECTIVES To test the assumption that fear of injury leads to disability and physical deconditioning in patients with chronic low back pain (CLBP) and to evaluate the relation between disability and physical deconditioning. DESIGN Survey in a cross-sectional design. SETTING A rehabilitation center in the Netherlands. PARTICIPANTS Forty patients with nonspecific CLBP. INTERVENTIONS Not applicable. MAIN OUTCOME MEASURES Fear of injury was measured with the Tampa Scale of Kinesiophobia. Physical fitness was expressed in aerobic fitness measured as predicted maximum oxygen consumption derived in a submaximal exercise test according the protocol of Siconolfi. Disability was measured with the Roland Disability Questionnaire. The association between fear of injury and physical fitness or disability was examined with correlational and multiple linear regression analyses. RESULTS Fear of injury correlated significantly with disability (r=.44), but did not correlate significantly with aerobic fitness. There was no statistically significant association between disability and aerobic fitness. Multiple regression analysis revealed that aerobic fitness was predicted by gender only. CONCLUSIONS Fear of injury appears to be more strongly associated with perceived disability than with aerobic fitness. The assumption that fear of injury leads to physical deconditioning was not confirmed in this sample of patients with CLBP.

Disability and quality of life in patients with fibromyalgia.

BackgroundPatients with fibromyalgia often feel disabled in the performance of daily activities. Psychological factors seem to play a pronounced disabling role in fibromyalgia.The objectives of the study are: Firstly, to investigate contributing factors for disability in fibromyalgia. Secondly, to study psychological distress in patients with fibromyalgia as compared to other nonspecific pain syndromes. And finally, to explore the impact of fibromyalgia on a patients quality of life.MethodsIn this cross sectional study, explaining factors for disability were studied based on a regression analysis with gender, mental health, physical and social functioning as independent variables. For the assessment of disability in fibromyalgia the FIQ was used. The levels of psychological distress in patients with fibromyalgia, Complex Regional Pain Syndrome (CRPS) and chronic low back pain (CLBP) were compared based on scores on the Symptom Checklist (SCL90). Quality of life of patients with fibromyalgia was compared with scores (SF36) of both patients with fibromyalgia and other health conditions as derived from the literature.ResultsDisability in fibromyalgia seemed best explained by a patients mental health condition (β = -0.360 p = 0.02). The level of psychological distress was higher in patients with fibromyalgia as compared to patients with CRPS or CLBP (p < 0.01). The impact of fibromyalgia on quality of life appeared to be high as compared to the impact of other health conditions.ConclusionPatients with fibromyalgia report a considerable impact on their quality of life and their perceived disability level seems influenced by their mental health condition. In comparison with patients with other pain conditions psychological distress is higher.

Relationship between physical activity and disability in low back pain: A systematic review and meta-analysis

&NA; It is often assumed that patients with pain‐related disability due to low back pain (LBP) will have reduced physical activity levels, but recent studies have provided results that challenge this assumption. The aim of our systematic review was to examine the relationship between physical activity and disability in LBP. The literature search included 6 electronic databases and the reference list of relevant systematic reviews and studies to May 2010. To be included, studies had to measure both disability (eg, with the Roland Morris Disability Questionnaire) and physical activity (eg, by accelerometry) in patients with non‐specific LBP. Two independent reviewers screened search results and extracted data, and authors were contacted for additional data. Correlation coefficients were pooled using the random‐effects model. The search identified 3213 records and 18 studies were eligible for inclusion. The pooled results showed a weak relationship between physical activity and disability in acute or subacute (<3 months) LBP (r = −0.08, 95% confidence interval = −0.17 to 0.002), and a moderate and negative relationship in chronic (>3 months) LBP (r = −0.33, 95% confidence interval = −0.51 to −0.15). That is, persons with acute or subacute LBP appear to vary in the levels of physical activity independent of their pain‐related disability. Persons with chronic LBP with high levels of disability are also likely to have low levels of physical activity. Persons with acute or subacute back pain appear to vary in the levels of physical activity independent of disability. Persons with chronic back pain with high levels of disability will likely have low levels of physical activity.

A longitudinal study on the predictive validity of the fear-avoidance model in low back pain

&NA; Recently, fear–avoidance models have been quite influential in understanding the transition from acute to chronic low back pain (LBP). Not only has pain‐related fear been found to be associated with disability and increased pain severity, but also treatment focused at reducing pain‐related fear has shown to successfully reduce disability levels. In spite of these developments, there is still a lack in well‐designed prospective studies examining the role of pain‐related fear in acute back pain. The aim of the current study was to prospectively test the assumption that pain‐related fear in acute stages successfully predicts future disability. Subjects were primary care acute LBP patients consulting because of a new episode of LBP (≤3 weeks). They completed questionnaires on background variables, fear–avoidance model variables and LBP outcome (Graded Chronic Pain Scale, GCPS) at baseline, 3, 6, and 12 months follow‐up and at the end of the study. Two‐hundred and twenty‐two acute LBP patients were included, of whom 174 provided full follow‐up information (78.4%). A backward ordinal regression analysis showed previous LBP history and pain intensity to be the most important predictors of end of study GCPS. Of the fear–avoidance model variables, only negative affect added to this model. Our results do not really support the longitudinal validity of the fear–avoidance model, but they do feed the discussion on the role of pain‐related fear in early stages of LBP.

Cause or effect? Deconditioning and chronic low back pain.

Physical inactivity is now universally accepted as the biggest public health problem of the 21st century in Western societies. Physical inactivity and the resulting physical deconditioning are associated with a host of chronic diseases of which non-specific chronic back pain (CLBP) may be one. The deconditioning paradigm hypothesizes that physical inactivity and physical deconditioning not only cause low back pain, but also contribute to ongoing intolerance of physical activities which leads to functional limitations and disability in self care and community participation [13]. According to the fear avoidance model patients may interpret their pain as threatening (catastrophizing), which can result in fear of movement, disuse (loss of physical activities in daily life (PAL)) and deconditioning, perpetuating pain, depression and disability [31]. It is unclear whether physical inactivity and deconditioning perpetuate chronicity of low back pain [28]. It has even been debated whether physical deconditioning in patients with non-specific CLBP really exists [23]. Although the influence of pain-related fear on disability has been confirmed across multiple diagnoses, its presumed negative influence on PAL in patients with non-specific CLBP is still inconclusive [3]. Nevertheless, intensive physical training remains a major component of most CLBP-treatments. While this may be an effective treatment strategy, is it being done for the wrong reasons? In this topical review, existing literature on physical inactivity and deconditioning in patients with non-specific CLBP is summarized. The impact of physical inactivity and deconditioning is reviewed in terms of the etiology of CLBP as well as the impact of the patients’ levels of physical activity and physical fitness on the chronicity of back pain. Recommendations for future research are provided.

Determinants of quality of life in survivors of cardiac arrest

OBJECTIVE To study factors related to quality of life after a hypoxic period due to cardiac arrest. DESIGN Retrospective cohort study. SUBJECTS Eighty-eight survivors of out-of-hospital cardiac arrest, admitted to a Dutch academic hospital between 2001 and 2006. METHODS Patients received a set of questionnaires at home. The main outcome measures were physical and mental quality of life (Medical Outcomes Study 36-item Short Form Health Survey; SF-36). Potential determinants were cognitive complaints, emotional problems depression/anxiety), post-traumatic stress, fatigue, daily functioning and participation in society. Multiple linear regression analyses were performed with physical and mental quality of life as dependent variables. RESULTS Sixty-three (72%) patients responded. Mean time since cardiac arrest was 36 months (standard deviation (SD) 19). Backward regression analyses showed that physical quality of life was significantly (p < 0.001, adjusted R2 = 0.531) related to cognitive complaints (beta = -0.378), instrumental daily life activities (beta = 0.262), post-traumatic stress (beta = -0.246) and fatigue (beta = -0.226). Mental quality of life was significantly (p < 0.001, adjusted R2 = 0.664) explained by anxiety/depression (beta = -0.609), fatigue (beta = -0.177) and cognitive complaints (beta = -0.175). CONCLUSION Quality of life is related to cognitive complaints, fatigue, anxiety/depression, post-traumatic stress and difficulties in daily activities in survivors of out-of-hospital cardiac arrest. Rehabilitation programmes for this group should specifically address these topics.