Missing data and imputation: a practical illustration in a prognostic study on low back pain.

Objective: When designing prediction models by complete case analysis (CCA), missing information in either baseline (predictors) or outcomes may lead to biased results. Multiple imputation (MI) has been shown to be suitable for obtaining unbiased results. This study provides researchers with an empirical illustration of the use of MI in a data set on low back pain, by comparing MI with the more commonly used CCA.

Minimal clinically important change on the Headache Impact Test-6 questionnaire in patients with chronic tension-type headache.

Objective: To determine the minimal clinically important change (MCIC) in Headache Impact Test-6 (HIT-6) score in patients with chronic tension-type headache (CTTH).

Methods: The HIT-6 was administered at baseline and at 8 weeks follow-up in a cohort of 186 participants with CTTH who received manual therapy or usual care by their general practitioner. An anchor-based method was used to determine the MCIC, with the external criterion (anchor) being based on general perceived improvement ('much improved or very much improved' on a 7-point Likert scale) in combination with 50% reduction in headache days.

Identifying generic predictors of outcome in patients presenting to primary care with nonspinal musculoskeletal pain.

Objective: To identify which generic prognostic factors, such as pain intensity, levels of disability, and psychological factors, are most strongly associated with outcome from musculoskeletal pain, regardless of the location of pain. We tested the hypothesis that pain location does not add predictive value to these generic prognostic models, and that such prognostic factors are equally important across different pain locations.

Methods: Data from a prospective observational cohort of primary care patients with acute (n = 413) and chronic (n = 414) nonspinal musculoskeletal pain were used to develop predictive models.

Clinical variables associated with recovery in patients with chronic tension-type headache after treatment with manual therapy.

The aims of this study were to describe the course of chronic tension-type headache (CTTH) in participants receiving manual therapy (MT), and to develop a prognostic model for predicting recovery in participants receiving MT. Outcomes in 145 adults with CTTH who received MT as participants in a previously published randomised clinical trial (n=41) or in a prospective cohort study (n=104) were evaluated. Assessments were made at baseline and at 8 and 26 weeks of follow-up.

Factors associated with the severity and progression of self-reported hand pain and functional difficulty in community-dwelling older adults: a systematic review.

Background: Hand problems are common in older adults and cause significant pain and disruption to everyday living. The aim of this systematic review was to summarize evidence on the factors associated with the severity and progression of self-reported hand pain and functional difficulty in population-based studies of older adults.

Methods: MEDLINE, EMBASE, CINAL, BNI, AMED, HMIC, PsycINFO and ISI Web of Knowledge were searched up to January 2011 for relevant articles.

Functional outcome in older adults with joint pain and comorbidity: design of a prospective cohort study.

Background: Joint pain is a highly prevalent condition in the older population. Only a minority of the older adults consult the general practitioner for joint pain, and during consultation joint pain is often poorly recognized and treated, especially when other co-existing chronic conditions are involved. Therefore, older adults with joint pain and comorbidity may have a higher risk of poor functional outcome and decreased quality of life (QoL), and possibly need more attention in primary care.

Magnetic resonance imaging for diagnosing lumbar spinal pathology in adult patients with low back pain or sciatica: a diagnostic systematic review.

Purpose: In about 5% of all cases LBP is associated with serious underlying pathology requiring diagnostic confirmation and directed treatment. Magnetic resonance imaging (MRI) is often used for this diagnostic purpose yet its role remains controversial. Consequently, this review aimed to summarize the available evidence on the diagnostic accuracy of MRI for identifying lumbar spinal pathology in adult low back pain (LPB) or sciatica patients.

Prediction of persistent shoulder pain in general practice: comparing clinical consensus from a Delphi procedure with a statistical scoring system.

Background: In prognostic research, prediction rules are generally statistically derived. However the composition and performance of these statistical models may strongly depend on the characteristics of the derivation sample. The purpose of this study was to establish consensus among clinicians and experts on key predictors for persistent shoulder pain three months after initial consultation in primary care and assess the predictive performance of a model based on clinical expertise compared to a statistically derived model.

Profiling dizziness in older primary care patients: an empirical study.

Background: The diagnostic approach to dizzy, older patients is not straightforward as many organ systems can be involved and evidence for diagnostic strategies is lacking. A first differentiation in diagnostic subtypes or profiles may guide the diagnostic process of dizziness and can serve as a classification system in future research. In the literature this has been done, but based on pathophysiological reasoning only.

The search for stable prognostic models in multiple imputed data sets.

Background: In prognostic studies model instability and missing data can be troubling factors. Proposed methods for handling these situations are bootstrapping (B) and Multiple imputation (MI). The authors examined the influence of these methods on model composition.

Effectiveness of manual therapy for chronic tension-type headache: a pragmatic, randomised, clinical trial.

Objective: To evaluate the effectiveness of manual therapy (MT) in participants with chronic tension-type headache (CTTH).

Subjects And Methods: We conducted a multicentre, pragmatic, randomised, clinical trial with partly blinded outcome assessment. Eighty-two participants with CTTH were randomly assigned to MT or to usual care by the general practitioner (GP).

Fatigue in primary care: longitudinal associations with pain.

So far, most studies on the association between pain and fatigue have used cross-sectional data. We analysed the possibilities for a temporal relationship between pain and fatigue in a cohort study of patients presenting with fatigue in primary care. Of 856 recruited patients, 642 (75%) completed postal questionnaires after the consultation, and at one, four, eight and 12 months follow-up, with completion rates ranging from 82% to 88%.

Negative association of concomitant physical symptoms with the course of major depressive disorder: a systematic review.

Objective: The prognosis of depression greatly varies among patients, and the physical symptoms that often accompany depression may predict treatment resistance and a worse outcome. If so, this may have important clinical implications. The aim of this systematic review was to explore the association of concomitant physical symptoms with the outcome of major depressive disorder (MDD).

Measuring practitioner/therapist effects in randomised trials of low back pain and neck pain interventions in primary care settings.

In psychological health treatment studies it has been shown that differences between therapists account for some of the non-specific effect of treatment but this phenomenon has not so far systematically been investigated in musculoskeletal disorders. In this study we evaluated and compared the size and potential influence of the 'practitioner effect' (or 'therapist effect') in three randomised treatment trials of low back pain and neck pain patients in primary care. We calculated the proportion of variance in outcomes attributable to differences across practitioners, i.

Diagnostic testing for celiac disease among patients with abdominal symptoms: a systematic review.

Context: The symptoms and consequences of celiac disease usually resolve with a lifelong gluten-free diet. However, clinical presentation is variable and most patients presenting with abdominal symptoms in primary care will not have celiac disease and unnecessary diagnostic testing should be avoided.

Objective: To summarize evidence on the performance of diagnostic tests for identifying celiac disease in adults presenting with abdominal symptoms in primary care or similar settings.

Value of symptoms and additional diagnostic tests for colorectal cancer in primary care: systematic review and meta-analysis.

Objective: To summarise available evidence on diagnostic tests that might help primary care physicians to identify patients with an increased risk for colorectal cancer among those consulting for non-acute lower abdominal symptoms.

Data Sources: PubMed, Embase, and reference screening. Study eligibility criteria Studies were selected if the design was a diagnostic study; the patients were adults consulting because of non-acute lower abdominal symptoms; tests included signs, symptoms, blood tests, or faecal tests.

Corticosteroid injection for de Quervain's tenosynovitis.

Background: De Quervain's tenosynovitis is a disorder characterised by pain on the radial (thumb) side of the wrist and functional disability of the hand. It can be treated by corticosteroid injection, splinting and surgery.

Objectives: To summarise evidence on the efficacy and safety of corticosteroid injections for de Quervain's tenosynovitis.

Diagnosis and management of patients with hand and wrist problems in general practice.

Objectives: 1) To describe diagnoses made by general practitioners (GPs) in patients with hand or wrist problems, 2) to describe management, and 3) to determine the association between diagnostic information and two outcomes: persistent symptoms and specialist referral.

Methods: GPs recruited patients with hand or wrist problems and completed a standardized form recording information about patient history, observations, palpation, and physical tests. Patients were sent a questionnaire at baseline, 3, and 12 months, containing questions on characteristics and symptom severity.

Co-occurrence and associations of pain and fatigue in a community sample of Dutch adults.

Widespread pain and chronic fatigue are common in the general population. Previous research has demonstrated co-occurrence of syndromes that are associated with pain and fatigue (fibromyalgia and chronic fatigue syndrome), but there is limited existing data on the co-occurrence of these symptoms in general. This study investigates the co-occurrence of pain and fatigue, and characterises people with these symptoms individually, and in combination.

Effectiveness of manual therapy compared to usual care by the general practitioner for chronic tension-type headache: design of a randomised clinical trial.

Background: Patients with Chronic Tension Type Headache (CTTH) report functional and emotional impairments (loss of workdays, sleep disturbances, emotional well-being) and are at risk for overuse of medication. Manual therapy may improve symptoms through mobilisation of the spine, correction of posture, and training of cervical muscles.We present the design of a randomised clinical trial (RCT) evaluating the effectiveness of manual therapy (MT) compared to usual care by the general practitioner (GP) in patients with CTTH.

Does age modify the relationship between morbidity severity and physical health in English and Dutch family practice populations?

Purpose: To investigate the co-influences of age and morbidity severity on physical health in adult family practice populations.

Methods: Morbidity data in a 12-month period for 7,833 older English consulters aged 50 years and over and 6,846 Dutch consulters aged 18 years and over was linked to their physical health status obtained from cross-sectional health surveys. Individual patients were categorised using 78 consulting morbidities classified by a chronicity measure (acute, acute-on-chronic and chronic) into an ordinal scale of morbidity severity ranging from single to multiple chronicity groups.

Corticosteroid injection for trigger finger in adults.

Background: Trigger finger is a disease of the tendons of the hand leading to triggering (locking) of affected fingers, dysfunction and pain. Available treatments include local injection with corticosteroids, surgery, or splinting.

Objectives: To summarize the evidence on the efficacy and safety of corticosteroid injections for trigger finger in adults using the following endpoints: treatment success, frequency of triggering or locking, functional status of the affected fingers, and severity of pain of the fingers.

Research priorities for non-pharmacological therapies for common musculoskeletal problems: nationally and internationally agreed recommendations.

Background: Musculoskeletal problems such as low back pain, neck, knee and shoulder pain are leading causes of disability and activity limitation in adults and are most frequently managed within primary care. There is a clear trend towards large, high quality trials testing the effectiveness of common non-pharmacological interventions for these conditions showing, at best, small to moderate benefits. This paper summarises the main lessons learnt from recent trials of the effectiveness of non-pharmacological therapies for common musculoskeletal conditions in primary care and provides agreed research priorities for future clinical trials.

Prognosis of fatigue and functioning in primary care: a 1-year follow-up study.

Purpose: Although fatigue is a common presenting symptom in primary care and its course and outcomes often remain unclear, cohort studies among patients seeking care for fatigue are scarce. We therefore aimed to investigate patterns in the course of fatigue and relevant secondary outcomes in a large cohort of patients who sought care for a main symptom of fatigue.

Methods: We performed an observational cohort study in 147 primary care practices.