%0 Journal Article %J Thromb Haemost %D 2011 %T Validation of the CHADS2 clinical prediction rule to predict ischaemic stroke. A systematic review and meta-analysis %A Keogh, C %A Wallace, E %A Dillon, C %A Dimitrov, B %A Fahey, T %K Atrial Fibrillation %K Humans %K Myocardial Ischemia %K Practice Guidelines as Topic %K Predictive Value of Tests %K Prognosis %K Quality Assurance, Health Care %K Research Design %K Risk %K Sensitivity and Specificity %K Stroke %X The CHADS2 predicts annual risk of ischaemic stroke in non-valvular atrial fibrillation. This systematic review and meta-analysis aims to determine the predictive value of CHADS2. The literature was systematically searched from 2001 to October 2010. Data was pooled and analysed using discrimination and calibration statistical measures, using a random effects model. Eight data sets (n = 2815) were included. The diagnostic accuracy suggested a cut-point of ≥ 1 has higher sensitivity (92%) than specificity (12%) and a cut-point of ≥ 4 has higher specificity (96%) than sensitivity (33%). Lower summary estimates were observed for cut-points ≥ 2 (sensitivity 79%, specificity 42%) and ≥ 3 (specificity 77%, sensitivity 50%). There was insufficient data to analyse cut-points ≥ 5 or ≥ 6. Moderate pooled c statistic values were identified for the classic (0.63, 95% CI 0.52-0.75) and revised (0.60, 95% CI 0.43-0.72) view of stratification of the CHADS2. Calibration analysis indicated no significant difference between the predicted and observed strokes across the three risk strata for the classic or revised view. All results were associated with high heterogeneity, and conclusions should be made cautiously. In conclusion, the pooled c statistic and calibration analysis suggests minimal clinical utility of both the classic and revised view of the CHADS2 in predicting ischaemic stroke across all risk strata. Due to high heterogeneity across studies and low event rates across all risk strata, the results should be interpreted cautiously. Further validation of CHADS2 should perhaps be undertaken, given the methodological differences between many of the available validation studies and the original CHADS2 derivation study. %B Thromb Haemost %V 106 %P 528-38 %8 2011 Sep %G eng %U http://th.schattauer.de/en/contents/archive/issue/1439/manuscript/16384.html %N 3 %R 10.1160/TH11-02-0061 %0 Journal Article %J QJM %D 2011 %T The risk of foot ulceration in people with diabetes screened in community settings: findings from a cohort study %A Crawford, F %A McCowan, Colin %A Dimitrov, B %A Woodburn, J %A Wylie, G H %A Booth, E %A Leese, G P %A Bekker, H L %A Kleijnen, J %A Fahey, T %K Adult %K Aged %K Aged, 80 and over %K Delivery of Health Care %K Diabetes Mellitus, Type 2 %K Diabetic Foot %K Diabetic Neuropathies %K Female %K Humans %K Male %K Mass Screening %K Middle Aged %K Predictive Value of Tests %K Risk Factors %K Scotland %X BACKGROUND: Annual foot checks are recommended in patients with diabetes mellitus (DM) to identify those at risk of foot ulceration. Systematic reviews have found few studies evaluating the predictive value of tests in community-based diabetic populations. AIM: To quantify the predictive value of clinical risk factors in relation to foot ulceration in a community population. METHODS: A cohort of 1192 people with diabetes receiving care in community settings was recruited and a screening procedure, covering symptoms, signs and diagnostic tests was conducted at baseline. At an average 1-year follow-up patients who developed a foot ulcer were identified by an independent blind assessor. Multivariable analysis was performed to identify clinical predictors of foot ulceration. FINDINGS: The incidence of foot ulceration was 1.93% [95% confidence interval (CI) 1.27-2.89). Three time-independent clinical predictors with five factors were selected: previous amputation [odds ratio (OR) 14.7, 95% CI 3.1-69.5), use of insulin before 3 months with inability to distinguish between cool and cold temperatures (OR 2.97, 95% CI 1.9-4.5) and failure to obtain at least one blood pressure reading for the calculation of ankle-brachial index with the failure to feel touch with a 10-g monofilament (OR 1.7, 95% CI 1.3-2.2). INTERPRETATION: Recommendations for annual diabetic foot check in low-risk, community-based patients should be reviewed as absolute events of ulceration are low. The accuracy of foot risk assessment tools to predict ulceration requires evaluation in randomized controlled trials with concurrent economic evaluations. %B QJM %V 104 %P 403-10 %8 2011 May %G eng %U http://qjmed.oxfordjournals.org/content/104/5/403 %N 5 %R 10.1093/qjmed/hcq227 %0 Journal Article %J Fam Pract %D 2011 %T Prognostic value of the ABCD² clinical prediction rule: a systematic review and meta-analysis %A Galvin, R %A Geraghty, Colm %A Motterlini, N %A Dimitrov, B %A Fahey, T %K Humans %K Ischemic Attack, Transient %K Predictive Value of Tests %K Risk Assessment %K Risk Factors %K Stroke %K Time Factors %X OBJECTIVE: The purpose of this systematic review with meta-analysis is to determine the predictive value of the ABCD ²at 7 and 90 days across three strata of risk. Background. The risk of stroke after transient ischaemic attack (TIA) is significant. The ABCD ²clinical prediction rule is designed to predict early risk of stroke after TIA. A number of independent validation studies have been conducted since the rule was derived. METHODS: A systematic literature search was conducted to identify studies that validated the ABCD². The derived rule was used as a predictive model and applied to subsequent validation studies. Comparisons were made between observed and predicted number of strokes stratified by risk group: low (0-3 points), moderate (4-5 points) and high (6-7 points). Pooled results are presented as risk ratios (RRs) with 95% confidence intervals (CIs), in terms of over-prediction (RR > 1) or under-prediction (RR < 1) of stroke at 7 and 90 days. RESULTS: We include 16 validation studies. Fourteen studies report 7-day stroke risk (n = 6282, 388 strokes). The ABCD² rule correctly predicts occurrence of stroke at 7 days across all three risk strata: low [RR 0.86, 95% CI (0.47-1.58), I² = 16%], moderate [RR 0.99, 95% CI (0.67-1.47), I² = 68%] and high [RR 0.84, 95% CI (0.6-1.19), I² = 46%]. Eleven studies report 90-day stroke risk (n = 6304). There is a non-significant trend towards over-prediction of stroke in all risk categories at 90 days. There are 426 strokes observed in contrast to a predicted 626 strokes. As the trichotomized ABCD² score increases, the risk of stroke increases (P < 0.01). There is no evidence of publication bias in these studies (P > 0.05). CONCLUSION: The ABCD² is a useful CPR, particularly in relation to 7-day risk of stroke. %B Fam Pract %V 28 %P 366-76 %8 2011 Aug %G eng %U http://fampra.oxfordjournals.org/content/28/4/366 %N 4 %R 10.1093/fampra/cmr008 %0 Journal Article %J BMC Med %D 2011 %T Predicting streptococcal pharyngitis in adults in primary care: a systematic review of the diagnostic accuracy of symptoms and signs and validation of the Centor score %A Aalbers, Jolien %A O'Brien, K %A Chan, Wai-Sun %A Falk, G %A Teljeur, C %A Dimitrov, B %A Fahey, T %K Adult %K Diagnosis, Differential %K Humans %K Pharyngitis %K Predictive Value of Tests %K Primary Health Care %K Streptococcal Infections %K Streptococcus pyogenes %X BACKGROUND: Stratifying patients with a sore throat into the probability of having an underlying bacterial or viral cause may be helpful in targeting antibiotic treatment. We sought to assess the diagnostic accuracy of signs and symptoms and validate a clinical prediction rule (CPR), the Centor score, for predicting group A β-haemolytic streptococcal (GABHS) pharyngitis in adults (> 14 years of age) presenting with sore throat symptoms. METHODS: A systematic literature search was performed up to July 2010. Studies that assessed the diagnostic accuracy of signs and symptoms and/or validated the Centor score were included. For the analysis of the diagnostic accuracy of signs and symptoms and the Centor score, studies were combined using a bivariate random effects model, while for the calibration analysis of the Centor score, a random effects model was used. RESULTS: A total of 21 studies incorporating 4,839 patients were included in the meta-analysis on diagnostic accuracy of signs and symptoms. The results were heterogeneous and suggest that individual signs and symptoms generate only small shifts in post-test probability (range positive likelihood ratio (+LR) 1.45-2.33, -LR 0.54-0.72). As a decision rule for considering antibiotic prescribing (score ≥ 3), the Centor score has reasonable specificity (0.82, 95% CI 0.72 to 0.88) and a post-test probability of 12% to 40% based on a prior prevalence of 5% to 20%. Pooled calibration shows no significant difference between the numbers of patients predicted and observed to have GABHS pharyngitis across strata of Centor score (0-1 risk ratio (RR) 0.72, 95% CI 0.49 to 1.06; 2-3 RR 0.93, 95% CI 0.73 to 1.17; 4 RR 1.14, 95% CI 0.95 to 1.37). CONCLUSIONS: Individual signs and symptoms are not powerful enough to discriminate GABHS pharyngitis from other types of sore throat. The Centor score is a well calibrated CPR for estimating the probability of GABHS pharyngitis. The Centor score can enhance appropriate prescribing of antibiotics, but should be used with caution in low prevalence settings of GABHS pharyngitis such as primary care. %B BMC Med %V 9 %P 67 %8 2011 %G eng %U http://www.biomedcentral.com/1741-7015/9/67 %R 10.1186/1741-7015-9-67 %0 Journal Article %J BMC Fam Pract %D 2010 %T Predicting acute uncomplicated urinary tract infection in women: a systematic review of the diagnostic accuracy of symptoms and signs %A Giesen, Leonie G M %A Cousins, G %A Dimitrov, B %A Van de Laar, F A %A Fahey, T %K Adult %K Bayes Theorem %K Female %K Humans %K Predictive Value of Tests %K Urinalysis %K Urinary Tract Infections %X BACKGROUND: Acute urinary tract infections (UTI) are one of the most common bacterial infections among women presenting to primary care. However, there is a lack of consensus regarding the optimal reference standard threshold for diagnosing UTI. The objective of this systematic review is to determine the diagnostic accuracy of symptoms and signs in women presenting with suspected UTI, across three different reference standards (10(2) or 10(3) or 10(5) CFU/ml). We also examine the diagnostic value of individual symptoms and signs combined with dipstick test results in terms of clinical decision making. METHODS: Searches were performed through PubMed (1966 to April 2010), EMBASE (1973 to April 2010), Cochrane library (1973 to April 2010), Google scholar and reference checking.Studies that assessed the diagnostic accuracy of symptoms and signs of an uncomplicated UTI using a urine culture from a clean-catch or catherised urine specimen as the reference standard, with a reference standard of at least ≥ 10(2) CFU/ml were included. Synthesised data from a high quality systematic review were used regarding dipstick results. Studies were combined using a bivariate random effects model. RESULTS: Sixteen studies incorporating 3,711 patients are included. The weighted prior probability of UTI varies across diagnostic threshold, 65.1% at ≥ 10(2) CFU/ml; 55.4% at ≥ 10(3) CFU/ml and 44.8% at ≥ 10(2) CFU/ml ≥ 10(5) CFU/ml. Six symptoms are identified as useful diagnostic symptoms when a threshold of ≥ 10(2) CFU/ml is the reference standard. Presence of dysuria (+LR 1.30 95% CI 1.20-1.41), frequency (+LR 1.10 95% CI 1.04-1.16), hematuria (+LR 1.72 95%CI 1.30-2.27), nocturia (+LR 1.30 95% CI 1.08-1.56) and urgency (+LR 1.22 95% CI 1.11-1.34) all increase the probability of UTI. The presence of vaginal discharge (+LR 0.65 95% CI 0.51-0.83) decreases the probability of UTI. Presence of hematuria has the highest diagnostic utility, raising the post-test probability of UTI to 75.8% at ≥ 10(2) CFU/ml and 67.4% at ≥ 10(3) CFU/ml. Probability of UTI increases to 93.3% and 90.1% at ≥ 10(2) CFU/ml and ≥ 10(3) CFU/ml respectively when presence of hematuria is combined with a positive dipstick result for nitrites. Subgroup analysis shows improved diagnostic accuracy using lower reference standards ≥ 10(2) CFU/ml and ≥ 10(3) CFU/ml. CONCLUSIONS: Individual symptoms and signs have a modest ability to raise the pretest-risk of UTI. Diagnostic accuracy improves considerably when combined with dipstick tests particularly tests for nitrites. %B BMC Fam Pract %V 11 %P 78 %8 2010 %G eng %U http://www.biomedcentral.com/1471-2296/11/78 %R 10.1186/1471-2296-11-78 %0 Journal Article %J Headache %D 2011 %T Diagnostic accuracy of the ID Migraine: a systematic review and meta-analysis %A Cousins, G %A Hijazze, Samira %A Van de Laar, F A %A Fahey, T %K Humans %K Migraine Disorders %K Predictive Value of Tests %K Reproducibility of Results %K Sensitivity and Specificity %X OBJECTIVE: The purpose of this systematic review with meta-analysis is to determine the diagnostic accuracy of the identification of migraine (ID Migraine) as a decision rule for identifying patients with migraine. BACKGROUND: The ID Migraine screening tool is designed to identify patients with migraine in primary care settings. Several studies have validated the ID Migraine across various clinical settings, including primary care, neurology departments, headache clinics, dental clinics, ear, nose, and throat (ENT) and ophthalmology. METHODS: A systematic literature search was conducted to identify all studies validating the ID Migraine, with the International Headache Criteria as the reference standard. The methodological quality of selected studies was assessed using the Quality of Diagnostic Accuracy Studies tool. All selected studies were combined using a bivariate random effects model. A sensitivity analysis was also conducted, pooling only those studies using representative patient groups (primary care, neurology departments, and headache clinics) to determine the potential influence of spectrum bias on the results. RESULTS: Thirteen studies incorporating 5866 patients are included. The weighted prior probability of migraine across the 13 studies is 59%. The ID Migraine is shown to be useful for ruling out rather than ruling in migraine, with a greater pooled sensitivity estimate (0.84, 95% confidence interval 0.75-0.90) than specificity (0.76, 95% confidence interval 0.69-0.83). A negative ID Migraine score reduces the probability of migraine from 59% to 23%. The sensitivity analysis reveals similar results. CONCLUSIONS: This systematic review quantifies the diagnostic accuracy of the ID Migraine as a brief, practical, and easy to use diagnostic tool for Migraine. Application of the ID Migraine as a diagnostic tool is likely to improve appropriate diagnosis and management of migraine sufferers. %B Headache %V 51 %P 1140-8 %8 2011 Jul-Aug %G eng %U http://onlinelibrary.wiley.com/doi/10.1111/j.1526-4610.2011.01916.x/abstract;jsessionid=D4B74FF3BAD1073878D910966C56835A.f03t04 %N 7 %R 10.1111/j.1526-4610.2011.01916.x %0 Journal Article %J BMJ %D 2009 %T Clinical prediction rules %A Falk, G %A Fahey, T %K Diagnosis %K Diagnostic Errors %K Family Practice %K Humans %K Likelihood Functions %K Predictive Value of Tests %K Questionnaires %K Unnecessary Procedures %B BMJ %V 339 %P b2899 %8 2009 %G eng %U http://www.ncbi.nlm.nih.gov/pubmed/19666679 %R 10.1136/bmj.b2899 %0 Journal Article %J BMC Med %D 2011 %T The Alvarado score for predicting acute appendicitis: a systematic review %A Ohle, Robert %A O'Reilly, Fran %A O'Brien, K %A Fahey, T %A Dimitrov, B %K Appendicitis %K Humans %K Predictive Value of Tests %K Severity of Illness Index %X BACKGROUND: The Alvarado score can be used to stratify patients with symptoms of suspected appendicitis; the validity of the score in certain patient groups and at different cut points is still unclear. The aim of this study was to assess the discrimination (diagnostic accuracy) and calibration performance of the Alvarado score. METHODS: A systematic search of validation studies in Medline, Embase, DARE and The Cochrane library was performed up to April 2011. We assessed the diagnostic accuracy of the score at the two cut-off points: score of 5 (1 to 4 vs. 5 to 10) and score of 7 (1 to 6 vs. 7 to 10). Calibration was analysed across low (1 to 4), intermediate (5 to 6) and high (7 to 10) risk strata. The analysis focused on three sub-groups: men, women and children. RESULTS: Forty-two studies were included in the review. In terms of diagnostic accuracy, the cut-point of 5 was good at 'ruling out' admission for appendicitis (sensitivity 99% overall, 96% men, 99% woman, 99% children). At the cut-point of 7, recommended for 'ruling in' appendicitis and progression to surgery, the score performed poorly in each subgroup (specificity overall 81%, men 57%, woman 73%, children 76%). The Alvarado score is well calibrated in men across all risk strata (low RR 1.06, 95% CI 0.87 to 1.28; intermediate 1.09, 0.86 to 1.37 and high 1.02, 0.97 to 1.08). The score over-predicts the probability of appendicitis in children in the intermediate and high risk groups and in women across all risk strata. CONCLUSIONS: The Alvarado score is a useful diagnostic 'rule out' score at a cut point of 5 for all patient groups. The score is well calibrated in men, inconsistent in children and over-predicts the probability of appendicitis in women across all strata of risk. %B BMC Med %V 9 %P 139 %8 2011 %G eng %U http://www.biomedcentral.com/1741-7015/9/139 %R 10.1186/1741-7015-9-139