Exhaled nitric oxide in the diagnosis of asthma in adults: a systematic review.

OBJECTIVES: To identify and synthesize evidence on the diagnostic accuracy of FE NO for asthma in adults. MATERIALS AND METHODS: Systematic searches (nine key biomedical databases and trial registers) were carried out on November 2014. Records were included if they recruited patients with the symptoms of asthma; used a single set of inclusion criteria; measured FE NO50 in accordance with American Thoracic Society guidelines, 2005 (off-line excluded); reported/allowed calculation of true-positive, true-negative, false-positive and false-negative patients as classified against any reference standard. Study quality was assessed using QUADAS II. Meta-analysis was planned where clinical study heterogeneity allowed. Rule-in and rule-out uses of FE NO were considered. RESULTS: A total of 4861 records were identified originally and 1312 in an update. Twenty-seven studies were included. Heterogeneity precluded meta-analysis. Results varied even within subgroups of studies. Cut-off values for the best sum of sensitivity and specificity varied from 12 to 55 p.p.b., but did not produce high accuracy. 100% sensitivity or 100% specificity was reported by some studies indicating potential use as a rule-in or rule-out strategy. CONCLUSIONS AND CLINICAL RELEVANCE: FE NO50 had variable diagnostic accuracy even within subgroups of studies with similar characteristics. Diagnostic accuracy, optimal cut-off values and best position for FE NO50 within a pathway remain poorly evidenced.

Systematic review of patient-reported outcome measures in patients with varicose veins.

BACKGROUND: Varicose veins can affect quality of life. Patient-reported outcome measures (PROMs) provide a direct report from the patient about the impact of the disease without interpretation from clinicians or anyone else. The aim of this study was to examine the quality of the psychometric evidence for PROMs used in patients with varicose veins. METHODS: A systematic review was undertaken to identify studies that reported the psychometric properties of generic and disease-specific PROMs in patients with varicose veins. Literature searches were conducted in databases including MEDLINE, up to July 2016. The psychometric criteria used to assess these studies were adapted from published recommendations in accordance with US Food and Drug Administration guidance. RESULTS: Nine studies were included which reported on aspects of the development and/or validation of one generic (36-Item Short Form Health Survey, SF-36®) and three disease-specific (Aberdeen Varicose Vein Questionnaire, AVVQ; Varicose Veins Symptoms Questionnaire, VVSymQ®; Specific Quality-of-life and Outcome Response - Venous, SQOR-V) PROMs. The evidence from included studies provided data to support the construct validity, test-retest reliability and responsiveness of the AVVQ. However, its content validity, including weighting of the AVVQ questions, was biased and based on the opinion of clinicians, and the instrument had poor acceptability. VVSymQ® displayed good responsiveness and acceptability rates. SF-36® was considered to have satisfactory responsiveness and internal consistency. CONCLUSION: There is a scarcity of psychometric evidence for PROMs used in patients with varicose veins. These data suggest that AVVQ and SF-36® are the most rigorously evaluated PROMs in patients with varicose veins.

Systematic review of carotid artery procedures and the volume-outcome relationship in Europe.

BACKGROUND: Hospitals that conduct more procedures on the carotid arteries may achieve better outcomes. In the context of ongoing reconfiguration of UK vascular services, this systematic review was conducted to evaluate the relationship between the volume of carotid procedures and outcomes, including mortality and stroke. METHODS: Searches of electronic databases identified studies that reported the effect of hospital or clinician volume on outcomes. Reference and citation searches were also performed. Inclusion was restricted to European populations on the basis that the model of healthcare delivery is similar across Europe, but differs from that in the USA and elsewhere. Analyses of hospital and clinician volume, and carotid endarterectomy (CEA) and carotid artery stenting (CAS) were conducted separately. RESULTS: Eleven eligible studies were identified (233 411 participants), five from the UK, two from Sweden, one each from Germany, Finland and Italy, and a combined German, Austrian and Swiss population. All studies were observational. Two large studies (179 736 patients) suggested an inverse relationship between hospital volume and mortality (number needed to treat (NNT) as low as 165), and combined mortality and stroke (NNT as low as 93), following CEA. The evidence was less clear for CAS; multiple analyses in three studies did not identify convincing evidence of an association. Limited data are available on the relationship between clinician volume and outcome in CAS; in CEA, an inverse relationship was identified by two of three small studies. CONCLUSION: The evidence from the largest and highest-quality studies included in this review support the centralization of CEA.

Systematic review and qualitative evidence synthesis of patient-reported outcome measures for abdominal aortic aneurysm.

BACKGROUND: The aim was to identify and evaluate existing patient-reported outcome measures (PROMs) for use in patients with an abdominal aortic aneurysm (AAA) to inform the selection for use in surgical practice. METHODS: Two reviews were conducted: a systematic review to identify valid, reliable and acceptable PROMs for patients with an AAA, and a qualitative evidence synthesis to assess the relevance to patients of the identified PROM items. PROM studies were evaluated for their psychometric properties using established assessment criteria, and for their methodological quality using the COSMIN checklist. Qualitative studies were synthesized using framework analysis, and concepts identified were then triangulated using a protocol with the item concepts of the identified PROMs. RESULTS: Four PROMs from three studies were identified in the first review: Short Form 36, Australian Vascular Quality of Life Index, Aneurysm Dependent Quality of Life (AneurysmDQoL) and Aneurysm Symptoms Rating Questionnaire (AneurysmSRQ). None of the identified PROMs had undergone a rigorous psychometric evaluation within the AAA population. Four studies were included in the qualitative synthesis, from which 28 concepts important to patients with an AAA were identified. The AneurysmDQoL and AneurysmSRQ together provided the most comprehensive assessment of these concepts. Fear of rupture, control, ability to forget about the condition and size of aneurysm were all concepts identified in the qualitative studies but not covered by items in the identified PROMs. CONCLUSION: Further research is needed to develop PROMs for AAA that are reliable, valid and acceptable to patients.

Procedure Volume and the Association with Short-term Mortality Following Abdominal Aortic Aneurysm Repair in European Populations: A Systematic Review.

OBJECTIVE: To evaluate the relationship between the volume of abdominal aortic aneurysm (AAA) procedures undertaken and the primary outcome of mortality in Europe. Previous systematic reviews of this relationship are outdated and are overwhelmingly based on US data. DATA SOURCES: Comprehensive searching within MEDLINE and other bibliographic databases supplemented by citation searching and hand-searching of journals was undertaken to identify studies that reported the effect of hospital or clinician volume on any reported outcomes in adult, European populations, undergoing AAA repair and published in the last 10 years. METHODS: Two reviewers conducted study selection with independent, duplicate data extraction and quality assessment. A planned meta-analysis was not conducted because of the high risk of bias, the likelihood of individual study subjects being included in more than one study and diversity in the clinical populations studied and methods used. RESULTS: Sixteen studies (n = 237,074 participants) from the UK (n = 11 studies), Germany (n = 3 studies), Norway (n = 1 study), and one from the UK and Sweden were included. Data in the included studies came from administrative databases and clinical registries incorporating a variety of clinical and procedural groups; the study quality was limited by the use of observational study designs. Overall, the evidence favoured the existence of an inverse volume outcome relationship between hospital volume and mortality. Insufficient evidence was available to reach conclusions on the relationship between clinician volume and outcome and between hospital or clinician volume and secondary outcomes including complications and length of hospital stay. CONCLUSIONS: The evidence from this review suggests a relationship between the hospital volume of AAA procedures conducted and short-term mortality; however, as volume typically represents a complex amalgamation of factors further research will be useful to identify the core characteristics of volume that influence improved outcomes.

Systematic review assessing the measurement properties of patient-reported outcomes for venous leg ulcers.

BACKGROUND: A variety of instruments have been used to assess outcomes for patients with venous leg ulcers. This study sought to identify, evaluate and recommend the most appropriate patient-reported outcome measures (PROMs) for English-speaking patients with venous leg ulcers. METHODS: This systematic review used a two-stage search approach. Electronic searches of major databases including MEDLINE were completed in October 2015, and then updated in July 2016. Additional studies were identified from citation checking. Study selection, data extraction and quality assessment were undertaken independently by at least two reviewers. Evaluation and summary of measurement properties of identified PROMs were done using standard and adapted study-relevant criteria. RESULTS: Ten studies with data for four generic PROMS and six condition-specific measures were identified. No generic PROM showed adequate content and criterion validity; however, the EuroQoL Five Dimensions (EQ-5D™), Nottingham Health Profile (NHP) and 12-item Short-Form Health Survey (SF-12®) had good acceptability. In general, the EQ-5D™ showed poor responsiveness in patients with venous leg ulcers. Most condition-specific PROMs demonstrated poor criterion and construct validity. Overall, there was some evidence of internal consistency for the Venous Leg Ulcer Quality of Life (VLU-QoL) and the Sheffield Preference-based Venous Ulcer questionnaire (SPVU-5D). Test-retest reliability was satisfactory for the Venous Leg Ulcer Self-Efficacy Tool (VeLUSET). CONCLUSION: The NHP and VLU-QoL questionnaire seemed the most suitable PROMs for use by clinicians. However, a valid condition-specific PROM is still required.