Methods for identifying surgical wound infection after discharge from hospital: a systematic review.

Background: Wound infections are a common complication of surgery that add significantly to the morbidity of patients and costs of treatment. The global trend towards reducing length of hospital stay post-surgery and the increase in day case surgery means that surgical site infections (SSI) will increasingly occur after hospital discharge. Surveillance of SSIs is important because rates of SSI are viewed as a measure of hospital performance, however accurate detection of SSIs post-hospital discharge is not straightforward. Methods: We conducted a systematic review of methods of post discharge surveillance for surgical wound infection and undertook a national audit of methods of post-discharge surveillance for surgical site infection currently used within United Kingdom NHS Trusts. Results: Seven reports of six comparative studies which examined the validity of post-discharge surveillance methods were located; these involved different comparisons and some had methodological limitations, making it difficult to identify an optimal method. Several studies evaluated automated screening of electronic records and found this to be a useful strategy for the identification of SSIs that occurred post discharge. The audit identified a wide range of relevant post-discharge surveillance programmes in England, Scotland and Wales and Northern Ireland; however, these programmes used varying approaches for which there is little supporting evidence of validity and/or reliability. Conclusion: In order to establish robust methods of surveillance for those surgical site infections that occur post discharge, there is a need to develop a method of case ascertainment that is valid and reliable post discharge. Existing research has not identified a valid and reliable method. A standardised definition of wound infection ( e. g. that of the Centres for Disease Control) should be used as a basis for developing a feasible, valid and reliable approach to defining post discharge SSI. At a local level, the method used to ascertain post discharge SSI will depend upon the purpose of the surveillance, the nature of available routine data and the resources available

Analysing outcome variables with floor effects due to censoring: a simulation study with longitudinal trial data

ackground: Randomised controlled trials (RCTs) are the gold standard to estimate treatment effects. When patients receive effective treatment over time they may reach the limit of a certain measurement scale. This phenomenon is known as censoring and lead to skewed distributions of the outcome variable with an excess of either low (floor effect) or high values (ceiling effect). Applying traditional methods such as linear mixed models to analyse this kind of longitudinal RCT data may result in bias of the regression parameters. To deal with floor effects due to censoring,  a tobit mixed model can be used. The objective of this study was to compare the results of longitudinal linear mixed model analyses with longitudinal tobit mixed model analyses.Methods: First, a simulation study was performed in which several situations of RCTs with floor effects were simulated. Second, data from an empirical RCT was analysed with both methods.Results: Although all analyses underestimated the intervention effects, the tobit mixed model performed much better than the linear mixed model in handling floor effects. However, with an increasing number of follow-up measurements in combination with a strong floor effect estimates from the tobit mixed model were also not accurate.Conclusion: tobit mixed model analysis should be used to estimate treatments effects in longitudinal RCTs with floor effects due to censoring.&nbsp

how to study determinants related to medication adherence in newly diagnosed polyarthritis patients for the development of a prediction instrument

Patient Preference and Adherence Dovepress Introduction: For patients with a chronic disease, the appropriate use of medication is the key to manage their illness. Adherence to medication is therefore important. Adherence can be divided into three parts: the initiation part, the execution phase, and the discontinuation part. Little is known about the determinants of the initiation part. For this reason, we describe the conduct of a stepwise procedure to study determinants of medication initiation for patients with a chronic disease. Methods/design: The stepwise procedure comprises of eliciting a list of all potential determinants via literature review, interviewing patients, and consulting an expert panel. This is followed by embedding the determinants in a theoretical framework, developing a questionnaire, and choosing adherence measurement methods. The consecutive steps that we conducted for the development of a tool for the prediction of adherence in our study sample of early arthritis patients are described. Discussion: Although we used a thorough procedure, there are still some pitfalls to take into account, such as the choice of theoretical framework. A strength of this study is that we use multiple adherence measurement methods and that we also take clinical outcomes into account

Construct validity and responsiveness of feasible composite disease activity measures for use in daily clinical practice in patients with psoriatic arthritis

OBJECTIVE: There is a need for a widely accepted comprehensive disease activity measure for use in daily practice in patients with psoriatic arthritis (PsA). For this reason, the 3-item Visual Analogue Scale (3VAS) and 4-item Visual Analogue Scale (4VAS) were developed. This study aimed to test construct validity and responsiveness of the 3VAS and 4VAS in a population of patients with newly diagnosed PsA receiving usual care. METHODS: Components of the 3VAS (physician global, patient global, patient skin) and 4VAS (physician global, patient pain, patient joint, patient skin) were scored on 0-10 VAS scales. Agreement of low disease activity (LDA) state between 3VAS/4VAS and other composite measures was tested using Venn diagrams. Construct validity and responsiveness (3-month interval) were assessed using Spearman correlation coefficients and standardised response means (SRM) with effect sizes (ES), respectively, following hypothesis generation. Both 3VAS/4VAS were also compared with several patient-reported outcome measures. RESULTS: Data from 629 patients were used. Both 3VAS (ES=0.48, SRM 0.52) and 4VAS (ES=0.48, SRM=0.50) showed responsiveness similar to Disease Activity in PSoriatic Arthritis (DAPSA) and Disease Activity Score-28 (DAS28). Both measures had a strong correlation with DAPSA (r=0.80-0.87), Psoriatic Arthritis Disease Activity Score (PASDAS) (r=0.89) and Routine Assessment of Patient Index Data 3 (RAPID3) (r=0.84-0.92). 3VAS and 4VAS had the highest agreement with PASDAS in categorising patients to LDA at 12 months. CONCLUSION: This is the first study assessing the performance of the 3VAS and 4VAS in an observational cohort of patients with early PsA. Both measures have promising performance characteristics, showing strong correlations and good discrimination with existing composite measures. The 4VAS may be the preferred version with better face validity.</p

Determinants of radiographic progression in early psoriatic arthritis:Insights from a real-world cohort

Objective Persistent articular inflammation in psoriatic arthritis (PsA) is associated with radiographic damage. Despite advances in diagnosis and therapy, radiographic structural damage remains prevalent in PsA. To elucidate this topic, we studied which baseline clinical characteristics determine radiographic progression. Methods For this analysis, data were used from DEPAR (Dutch South West Psoriatic Arthritis) Study, a real-world cohort of patients with newly diagnosed PsA. Radiographic changes were assessed using the modified Total Sharp/van der Heijde Score (mTSS) for PsA. Univariable-multivariable mixed-effects negative binomial regression analysis was applied to define baseline predictors for radiographic progression over time. Results The study included 476 patients with early PsA with 1660 hand and feet radiographs from four different time points (baseline, first, second and third year). The progressive group (n=71) had a higher mTSS compared with the non-progressive group (n=405) at diagnosis (17 (3-36) vs 0 (0-1)). A comparison of the two groups revealed that the progressive group had significantly older (59 (12) vs 49 (13)) and a higher rate of the presence of swollen joints (93% vs 78%) at diagnosis. Multivariable analysis identified age (incidence rate ratio (IRR)=1.10, p=0.000), sex (female) (IRR=0.48, p=0.043) and baseline mTSS (IRR=1.11, p=0.000) as significant determinants of radiographic change over time. For the progressive subset, additionally, the multivariable analysis highlighted baseline Disease Activity in PSoriatic Arthritis (IRR=1.05, p=0.006) and swollen joint count (IRR=1.07, p=0.034) as predictors. Conclusions According to this real-world cohort, patients with early PsA exhibit minimal radiographic progression under current treatment protocols. This study indicates that while old age and initial radiographic damage predict progression, female sex confers a protective effect on it. Furthermore, disease activity score and swollen joints emerged as predictors for radiographic changes during the follow-up in progressive patients.</p

Determinants of radiographic progression in early psoriatic arthritis:Insights from a real-world cohort

Objective Persistent articular inflammation in psoriatic arthritis (PsA) is associated with radiographic damage. Despite advances in diagnosis and therapy, radiographic structural damage remains prevalent in PsA. To elucidate this topic, we studied which baseline clinical characteristics determine radiographic progression. Methods For this analysis, data were used from DEPAR (Dutch South West Psoriatic Arthritis) Study, a real-world cohort of patients with newly diagnosed PsA. Radiographic changes were assessed using the modified Total Sharp/van der Heijde Score (mTSS) for PsA. Univariable-multivariable mixed-effects negative binomial regression analysis was applied to define baseline predictors for radiographic progression over time. Results The study included 476 patients with early PsA with 1660 hand and feet radiographs from four different time points (baseline, first, second and third year). The progressive group (n=71) had a higher mTSS compared with the non-progressive group (n=405) at diagnosis (17 (3-36) vs 0 (0-1)). A comparison of the two groups revealed that the progressive group had significantly older (59 (12) vs 49 (13)) and a higher rate of the presence of swollen joints (93% vs 78%) at diagnosis. Multivariable analysis identified age (incidence rate ratio (IRR)=1.10, p=0.000), sex (female) (IRR=0.48, p=0.043) and baseline mTSS (IRR=1.11, p=0.000) as significant determinants of radiographic change over time. For the progressive subset, additionally, the multivariable analysis highlighted baseline Disease Activity in PSoriatic Arthritis (IRR=1.05, p=0.006) and swollen joint count (IRR=1.07, p=0.034) as predictors. Conclusions According to this real-world cohort, patients with early PsA exhibit minimal radiographic progression under current treatment protocols. This study indicates that while old age and initial radiographic damage predict progression, female sex confers a protective effect on it. Furthermore, disease activity score and swollen joints emerged as predictors for radiographic changes during the follow-up in progressive patients.</p

Very different performance of the power Doppler modalities of several ultrasound machines ascertained by a microvessel flow phantom

INTRODUCTION: In many patients with rheumatoid arthritis (RA) subclinical disease activity can be detected with ultrasound (US), especially using power Doppler US (PDUS). However, PDUS may be highly dependent on the type of machine. This could create problems both in clinical trials and in daily clinical practice. To clarify how the PDUS signal differs between machines we created a microvessel flow phantom. METHODS: The flow phantom contained three microvessels (150, 1000, 2000 microns). A syringe pump was used to generate flows. Five US machines were used. Settings were optimised to assess the lowest detectable flow for each US machine. RESULTS: The minimal detectable flow velocities showed very large differences between the machines. Only two of the machines may be able to detect the very low flows in the capillaries of inflamed joints. There was no clear relation with price. One of the lower-end machines actually performed best in all three vessel sizes. CONCLUSIONS: We created a flow phantom to test the sensitivity of US machines to very low flows in small vessels. The sensitivity of the power Doppler modalities of 5 different machines was very different. The differences found between the machines are probably caused by fundamental differences in processing of the PD signal or internal settings inaccessible to users. Machines considered for PDUS assessment of RA patients should be tested using a flow phantom similar to ours. Within studies, only a single machine type should be used

The pectoralis minor length test: a study of the intra-rater reliability and diagnostic accuracy in subjects with and without shoulder symptoms

This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly citedBackground. Postural abnormality and muscle imbalance are thought to contribute to pain and a loss of normal function in the upper body. A shortened pectoralis minor muscle is commonly identified as part of this imbalance. Clinical tests have been recommended to test for shortening of this muscle. The aim of this study was to evaluate the intra-rater reliability and diagnostic accuracy of the pectoralis minor length test. Methods. Measurements were made in 45 subjects with and 45 subjects without shoulder symptoms. Measurements were made with the subjects lying in supine. In this position the linear distance from the treatment table to the posterior aspect of the acromion was measured on two occasions (separated by a minimum of 30 minutes and additional data collection on other subjects to reduce bias) by one rater. The reliability of the measurements was analyzed using intraclass correlation coefficients (ICC), 95% confidence intervals (CI) and standard error of measurement (SEM). The diagnostic accuracy of the test was investigated by determining the sensitivity, specificity, positive and negative likelihood ratios of the test against a 'gold standard' reference. The assessor remained 'blinded' to data input and the measurements were staggered to reduce examiner bias. Results. The pectoralis minor length test was found to have excellent intra-rater reliability for dominant and non-dominant side of the subjects without symptoms, and for the painfree and painful side of the subjects with symptoms. The values calculated for the sensitivity, specificity, positive and negative likelihood ratios suggest this test performed in the manner investigated in this study and recommended in the literature, lacks diagnostic accuracy. Conclusion. The findings of this study suggest that although the pectoralis minor length test demonstrates acceptable clinical reliability, its lack of specificity suggests that clinicians using this test to inform the clinical reasoning process with regard treatment planning must do so with caution. Trial registration. National Research Register: N0060148286.Peer reviewe

Analyzing musculoskeletal neck pain, measured as present pain and periods of pain, with three different regression models: a cohort study

<p>Abstract</p> <p>Background</p> <p>In the literature there are discussions on the choice of outcome and the need for more longitudinal studies of musculoskeletal disorders. The general aim of this longitudinal study was to analyze musculoskeletal neck pain, in a group of young adults. Specific aims were to determine whether psychosocial factors, computer use, high work/study demands, and lifestyle are long-term or short-term factors for musculoskeletal neck pain, and whether these factors are important for developing or ongoing musculoskeletal neck pain.</p> <p>Methods</p> <p>Three regression models were used to analyze the different outcomes. Pain at present was analyzed with a marginal logistic model, for number of years with pain a Poisson regression model was used and for developing and ongoing pain a logistic model was used. Presented results are odds ratios and proportion ratios (logistic models) and rate ratios (Poisson model). The material consisted of web-based questionnaires answered by 1204 Swedish university students from a prospective cohort recruited in 2002.</p> <p>Results</p> <p>Perceived stress was a risk factor for pain at present (PR = 1.6), for developing pain (PR = 1.7) and for number of years with pain (RR = 1.3). High work/study demands was associated with pain at present (PR = 1.6); and with number of years with pain when the demands negatively affect home life (RR = 1.3). Computer use pattern (number of times/week with a computer session ≥ 4 h, without break) was a risk factor for developing pain (PR = 1.7), but also associated with pain at present (PR = 1.4) and number of years with pain (RR = 1.2). Among life style factors smoking (PR = 1.8) was found to be associated to pain at present. The difference between men and women in prevalence of musculoskeletal pain was confirmed in this study. It was smallest for the outcome ongoing pain (PR = 1.4) compared to pain at present (PR = 2.4) and developing pain (PR = 2.5).</p> <p>Conclusion</p> <p>By using different regression models different aspects of neck pain pattern could be addressed and the risk factors impact on pain pattern was identified. Short-term risk factors were perceived stress, high work/study demands and computer use pattern (break pattern). Those were also long-term risk factors. For developing pain perceived stress and computer use pattern were risk factors.</p

An evaluation of the structural validity of the Shoulder Pain and Disability Index (SPADI) using the Rasch model

Purpose: The Shoulder Pain and Disability Index (SPADI) has been extensively evaluated for its psychometric properties using classic test theory (CTT). The purpose of this study was to evaluate its structural validity using Rasch model analysis. Methods: Responses to the SPADI from 1030 patients referred for physiotherapy with shoulder pain and enrolled in a prospective cohort study were available for Rasch model analysis. Overall fit, individual person and item fit, response format, dependence, unidimensionality, targeting, reliability and differential item functioning (DIF) were examined. Results: The SPADI pain subscale initially demonstrated a misfit due to DIF by age and gender. After iterative analysis it showed good fit to the Rasch model with acceptable targeting and unidimensionality (overall fit (chi-square statistic 57.2, p=0.1); mean item fit residual 0.19 (1.5) and mean person fit residual 0.44 (1.1); person separation index (PSI) of 0.83). The disability subscale however shows significant misfit due to uniform DIF even after iterative analyses were used to explore different solutions to the sources of misfit (overall fit (chi-square statistic 57.2, p=0.1); mean item fit residual -0.54 (1.26) and mean person fit residual -0.38 (1.0); PSI 0.84). Conclusions: Rasch Model analysis of the SPADI has identified some strengths and limitations not previously observed using CTT methods. The SPADI should be treated as two separate subscales. The SPADI is a widely used outcome measure in clinical practice and research, however the scores derived from it must be interpreted with caution. The pain subscale fits the Rasch model expectations well. The disability subscale does not fit the Rasch model and its current format does not meet the criteria for true interval-level measurement required for use as a primary endpoint in clinical trials. Clinicians should therefore exercise caution when interpreting score changes on the disability subscale and attempt to compare their scores to age and sex stratified data