J. André Knottnerus

Multimorbidity in General Practice: Prevalence, Incidence, and Determinants of Co-Occurring Chronic and Recurrent Diseases

Increasing numbers of people are found to have two or more diseases at the same time, which is termed multimorbidity. We studied the prevalence, incidence, and determinants of multimorbidity and the statistical clustering of chronic and recurrent diseases in a general practice setting. Prevalence of multimorbidity increased with all age groups from 10% in the 0-19-year-old age group up to 78% in subjects aged 80 and over. Increasing age, lower level of education, and public health insurance were related to the occurrence of morbidity, but even more strongly to the occurrence and degree of multimorbidity. The one-year incidence of multimorbidity (the new occurrence of two or more diseases in one year) was related to increasing age, public health insurance, and the presence of prevalent diseases at baseline. Statistical clustering of diseases was stronger than expected, especially among the younger subjects.

Comorbidity or multimorbidity: what's in a name? A review of literature

Aim: Comorbidity is increasingly prevalent. Moreover, many different definitions and interpretations of this phenomenon are used. Because of its social and clinical significance, it is important th...

Systematic Review and Meta‐analysis of Incidence Studies of Epilepsy and Unprovoked Seizures

Summary:  Purpose: To evaluate the methodology of incidence studies of epilepsy and unprovoked seizures and to assess the value of their findings by summarizing their results.

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.

Active rehabilitation for chronic low back pain: Cognitive-behavioral, physical, or both? First direct post-treatment results from a randomized controlled trial [ISRCTN22714229]

BackgroundThe treatment of non-specific chronic low back pain is often based on three different models regarding the development and maintenance of pain and especially functional limitations: the deconditioning model, the cognitive behavioral model and the biopsychosocial model.There is evidence that rehabilitation of patients with chronic low back pain is more effective than no treatment, but information is lacking about the differential effectiveness of different kinds of rehabilitation. A direct comparison of a physical, a cognitive-behavioral treatment and a combination of both has never been carried out so far.MethodsThe effectiveness of active physical, cognitive-behavioral and combined treatment for chronic non-specific low back pain compared with a waiting list control group was determined by performing a randomized controlled trial in three rehabilitation centers.Two hundred and twenty three patients were randomized, using concealed block randomization to one of the following treatments, which they attended three times a week for 10 weeks: Active Physical Treatment (APT), Cognitive-Behavioral Treatment (CBT), Combined Treatment of APT and CBT (CT), or Waiting List (WL). The outcome variables were self-reported functional limitations, patients main complaints, pain, mood, self-rated treatment effectiveness, treatment satisfaction and physical performance including walking, standing up, reaching forward, stair climbing and lifting. Assessments were carried out by blinded research assistants at baseline and immediately post-treatment. The data were analyzed using the intention-to-treat principle.ResultsFor 212 patients, data were available for analysis. After treatment, significant reductions were observed in functional limitations, patients main complaints and pain intensity for all three active treatments compared to the WL. Also, the self-rated treatment effectiveness and satisfaction appeared to be higher in the three active treatments. Several physical performance tasks improved in APT and CT but not in CBT. No clinically relevant differences were found between the CT and APT, or between CT and CBT.ConclusionAll three active treatments were effective in comparison to no treatment, but no clinically relevant differences between the combined and the single component treatments were found.

Problems in determining occurrence rates of multimorbidity

This article describes methodological decisions that have to be made when studying multiple pathology and presents appropriate analytical techniques. The main question of this article is: how can comorbidity and multimorbidity be operationalized with respect to the number and type of diseases studied, and which analytic approaches are available for the evaluation of multiple pathology? Choices regarding the number and type of diseases studied have great impact on the observed incidence and prevalence rates of comorbidity and multimorbidity. These rates are largely dependent on age, sex, and other determinants. In addition to crude descriptive measures, odds ratios and relative risks can be used to study comorbidity, whereas multimorbidity can be studied using observed/expected ratios. While basic analyses of comorbidity can be performed using standard statistical packages, two additional programs were developed for the analysis of the distribution of multimorbidity and statistically unexpected comorbidity, respectively. As some analyses are addressing multicomparisons, external validity testing is recommended.

The diagnostic value of the measurement of the ankle-brachial systolic pressure index in primary health care☆

We investigated the value of the ankle-brachial systolic pressure index (ABPI) as a test for the diagnosis of peripheral arterial occlusive disease (PAOD) in general practice. ABPI measurements on 231 legs of 117 subjects performed in three general practice centers (GPC) were compared with the diagnostic conclusions of a Vascular Laboratory. The optimum cutoff value for the ABPI, its accuracy and diagnostic value were estimated. In a subpopulation of 51 subjects for whom repeated measurements were available, we checked whether taking the mean of three consecutive ABPIs for test outcome would enhance diagnostic performance. Receiver Operating Characteristic analysis showed that overall performance of the GPC ABPI was good (area under the curve approximately 0.9). Performing repeated ABPI measurements was superior to performing a single measurement. The optimum cutoff value for the ABPI was 0.97, associated with a diagnostic odds ratio (OR) of 17 and an accuracy of 81%. In a somewhat more selected subpopulation, the optimum cutoff value was 0.92 (OR 70, accuracy 90%). On the basis of our results, we suggest the following rule of thumb: if the ABPI < 0.8 or if the mean of three ABPIs < 0.9, it is highly probable that PAOD is present (PV+ > or = 95%); if the ABPI > 1.1 or if the mean of three ABPIs > 1.0, PAOD can be ruled out (PV- > or = 99%). In conclusion, in primary health care, the ABPI measurement can be a useful supplementary test in ambiguous diagnostic situations with regard to PAOD.

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.

Summed score of the Patient Health Questionnaire-9 was a reliable and valid method for depression screening in chronically ill elderly patients

OBJECTIVE To assess the psychometric properties of the Patient Health Questionnaire-9 (PHQ-9) as a screening instrument for depression in elderly patients with diabetes mellitus (DM) and chronic obstructive pulmonary disease (COPD) without known depression. STUDY DESIGN AND SETTING DM and COPD patients aged >59 years were selected from general practices. A test-retest was conducted in 105 patients. Criterion validity, using the Mini International Neuropsychiatric Interview psychiatric interview to diagnose major depressive disorder (MDD) and any depressive disorder (ADD) as diagnostic standard, was evaluated for both summed and algorithm-based PHQ-9 score in 713 patients. Correlations with quality of life and severity of illness were calculated to assess construct validity. RESULTS Cohens kappa for the algorithm-based score was 0.71 for MDD and 0.69 for ADD. Correlation for test-retest assessment of the summed score was 0.91. The algorithm-based score had low sensitivity and high specificity, but both sensitivity and specificity were high for the optimal cut-off point of 6 on the summed score for ADD (Se 95.6%, Sp 81.0%). Correlations between summed score and quality of life and severity of illness were acceptable. CONCLUSION The summed PHQ-9 score seems a valid and reliable screening instrument for depression in elderly primary care patients with DM and COPD.

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.