Probability revision

This article examines the principles of probability revision and four different ways of obtaining post-test probabilities: the hypothetical cohort method, likelihood ratios and odds, the Nomogram, and precalculation. The authors then show where pre-test probabilities can be obtained, and then how to interpret multiple tests

Mammographic screening trials for women aged under 50. A quality assessment and meta-analysis

Objective: To carry out a systemic quality review and meta-analysis of all randomised trials of mammographic screening that included women aged under 50 years. Data sources: Reports of randomised trials of mammographic screening were identified via MEDLINE and checks of the bibliographies of retrieved articles and reviews. Data synthesis: Identified trials were assessed for: (i) method of randomisation; (ii) documented comparability of baseline data; (iii) standardised criteria for breast cancer death; (iv) use of an 'intention-to-treat analysis'. Seven randomised trials including almost 160 000 women aged under 50 were studied. The combined estimate of relative risk was 0.95 (95% confidence interval, 0.77-1.18), a statistically non-significant reduction of 5%. Adjustment for the cluster randomisation of two trials, and for degree of compliance, did not substantially change this result. Conclusions: These analyses suggest little, if any, benefit for women under 50 years of age. The results are not explained by the quality of the trials or the radiology. We recommend that women in this age group intending to be screened should be fully informed of these results

Antibiotics for sore throat.

Sore throat is a very common reason for people to attend for medical care. Sore throat is a disease that remits spontaneously, that is, 'cure' is not dependant on treatment. Nonetheless primary care doctors commonly prescribe antibiotics for sore throat and other upper respiratory tract infections.To assess the benefits of antibiotics in the management of sore throat.Systematic search of the literature from 1945 to 1999, using electronic searches of MEDLINE (using the keywords, "pharyngitis", "sore throat" and "tonsillitis") after 1966, the Cochrane Library, the Cochrane collection of hand-searched trials, and the reference sections of the articles identified. Abstracts of identified articles were used to determine which studies were trials.Trials of antibiotic against control with either measures of the typical symptoms (throat soreness, headache or fever), or complications (suppurative and non-suppurative) of sore throat.RevMan 4.0.3A total number of 10,484 cases of sore throat have been studied. 1. Non-suppurative complications There was a trend for protection against acute glomerulonephritis by antibiotics, but insufficient cases were recorded to be sure of this effect. Several studies found benefit from antibiotics for acute rheumatic fever, which reduced this complication to less than one third (OR = 0.30; 95% CI = 0.20-0.45). 2. Suppurative complications Antibiotics reduced the incidence of acute otitis media to about one quarter of that in the placebo group (OR = 0.22; 95% CI = 0.11-0.43) and reduced the incidence of acute sinusitis to about one half of that in the placebo group (OR = 0.46; 95% CI = 0.10-2.05). The incidence of quinsy was also reduced in relation to placebo group (OR = 0.18; 95% CI = 0.08-0.43). 3. Symptoms Symptoms of headache, throat soreness and fever were reduced by antibiotics to about one half. The greatest time for this to be evident was at about three and a half days (when the symptoms of about 50% of untreated patients had settled). About 90% of treated and untreated patients were symptom-free by one week. 4. Subgroup analyses of symptom reduction Subgroup analysis by age; blind vs unblinded; us of antipyretics; or results of swabs for Streptococcus yielded no significant differences.Antibiotics confer relative benefits in the treatment of sore throat. However, the absolute benefits are modest. Protecting sore throat sufferers against suppurative and non-suppurative complications in modern Western society can only be achieved by treating many with antibiotics who will derive no benefit. Antibiotics shorten the duration of symptoms, but by a mean of only about half of one day at day 3 (the time of maximal effect), and by about eight hours overall

Tonsillectomy or adenotonsillectomy versus non-surgical treatment for chronic/recurrent acute tonsillitis

Background Surgical removal of the tonsils, with or without adenoidectomy (adeno-/tonsillectomy), is a common ENT operation, but th e indicationsfor surgery are controversial. This is an update of a Cochrane re view first published in The Cochrane Library in Issue 3, 1999 andpreviously updated in 2009. Objectives To assess the effectiveness of tonsillectomy (with and without adenoidectomy) in children and adults with chr onic/recurrent acutetonsillitis in reducing the number and severity of episodes of tonsillitis or sore throat. Search methods We searched the Cochrane Ear, Nose and Throat Disorders Group Trials Register; the Cochrane Central Register of Controlled Trials(CENTRAL); PubMed; EMBASE; CINAHL; Web of S cie nce; Cambridge Scientific Abstracts; ISRCTN and additional sources forpublished and unpublished trials. The date of the most recent search was 30 June 2014. Selection criteria Randomised controlled trials comparing tonsillectomy (with or without adenoidectomy) with non-surgical treatment in adults andchildren with chronic/recurrent acute tonsillitis. Data collection and analysis We used the standard methodological procedures expected by The Cochrane Collaboration

Antibiotics for acute otitis media in children

Item does not contain fulltextBACKGROUND: Acute otitis media (AOM) is one of the most common diseases in early infancy and childhood. Antibiotic use for AOM varies from 56% in the Netherlands to 95% in the USA, Canada and Australia. This is an update of a Cochrane review first published in The Cochrane Library in Issue 1, 1997 and previously updated in 1999, 2005, 2009 and 2013. OBJECTIVES: To assess the effects of antibiotics for children with AOM. SEARCH METHODS: We searched CENTRAL (2015, Issue 3), MEDLINE (1966 to April week 3, 2015), OLDMEDLINE (1958 to 1965), EMBASE (January 1990 to April 2015), Current Contents (1966 to April 2015), CINAHL (2008 to April 2015) and LILACS (2008 to April 2015). SELECTION CRITERIA: Randomised controlled trials (RCTs) comparing 1) antimicrobial drugs with placebo and 2) immediate antibiotic treatment with expectant observation (including delayed antibiotic prescribing) in children with AOM. DATA COLLECTION AND ANALYSIS: Two review authors independently assessed trial quality and extracted data. MAIN RESULTS: For the review of antibiotics against placebo, 13 RCTs (3401 children and 3938 AOM episodes) from high-income countries were eligible and had generally low risk of bias. The combined results of the trials revealed that by 24 hours from the start of treatment, 60% of the children had recovered whether or not they had placebo or antibiotics. Pain was not reduced by antibiotics at 24 hours (risk ratio (RR) 0.89, 95% confidence interval (CI) 0.78 to 1.01) but almost a third fewer had residual pain at two to three days (RR 0.70, 95% CI 0.57 to 0.86; number needed to treat for an additional beneficial outcome (NNTB) 20). A quarter fewer had pain at four to seven days (RR 0.76, 95% CI 0.63 to 0.91; NNTB 16) and two-thirds fewer had pain at 10 to 12 days (RR 0.33, 95% CI 0.17 to 0.66; NNTB 7) compared with placebo. Antibiotics did reduce the number of children with abnormal tympanometry findings at two to four weeks (RR 0.82, 95% CI 0.74 to 0.90; NNTB 11), at six to eight weeks (RR 0.88, 95% CI 0.78 to 1.00; NNTB 16) and the number of children with tympanic membrane perforations (RR 0.37, 95% CI 0.18 to 0.76; NNTB 33) and halved contralateral otitis episodes (RR 0.49, 95% CI 0.25 to 0.95; NNTB 11) compared with placebo. However, antibiotics neither reduced the number of children with abnormal tympanometry findings at three months (RR 0.97, 95% CI 0.76 to 1.24) nor the number of children with late AOM recurrences (RR 0.93, 95% CI 0.78 to 1.10) when compared with placebo. Severe complications were rare and did not differ between children treated with antibiotics and those treated with placebo. Adverse events (such as vomiting, diarrhoea or rash) occurred more often in children taking antibiotics (RR 1.38, 95% CI 1.19 to 1.59; number needed to treat for an additional harmful outcome (NNTH) 14). Funnel plots do not suggest publication bias. Individual patient data meta-analysis of a subset of included trials found antibiotics to be most beneficial in children aged less than two years with bilateral AOM, or with both AOM and otorrhoea.For the review of immediate antibiotics against expectant observation, five trials (1149 children) from high-income countries were eligible and had low to moderate risk of bias. Four trials (1007 children) reported outcome data that could be used for this review. From these trials, data from 959 children could be extracted for the meta-analysis of pain at three to seven days. No difference in pain was detectable at three to seven days (RR 0.75, 95% CI 0.50 to 1.12). One trial (247 children) reported data on pain at 11 to 14 days. Immediate antibiotics were not associated with a reduction in the number of children with pain (RR 0.91, 95% CI 0.75 to 1.10) compared with expectant observation. Additionally, no differences in the number of children with abnormal tympanometry findings at four weeks, tympanic membrane perforations and AOM recurrence were observed between groups. No serious complications occurred in either the antibiotic or the expectant observation group. Immediate antibiotics were associated with a substantial increased risk of vomiting, diarrhoea or rash compared with expectant observation (RR 1.71, 95% CI 1.24 to 2.36; NNTH 9).Results from an individual patient data meta-analysis including data from six high-quality trials (1643 children) that were also included as individual trials in our review showed that antibiotics seem to be most beneficial in children younger than two years of age with bilateral AOM (NNTB 4) and in children with both AOM and otorrhoea (NNTB 3). AUTHORS' CONCLUSIONS: This review reveals that antibiotics have no early effect on pain, a slight effect on pain in the days following and only a modest effect on the number of children with tympani

Current guidelines poorly address multimorbidity: pilot of the interaction matrix method

Objectives: To develop a framework to identify and classify interactions within and among treatments and conditions and to test this framework with guidelines on chronic heart failure (CHF) and its frequent comorbidity. Study Design and Setting: Text analysis of evidence-based clinical practice guidelines on CHF and 18 conditions co-occurring in >= 5% of CHF patients (2-4 guidelines per disease). We extracted data on interactions between CHF and comorbidity and key recommendations on diagnostic and therapeutic management. From a subset of data, we derived 13 subcategories within disease-disease (Di-Di-I), disease-drug (Di-D-I), drug-drug interactions (DDI) and synergistic treatments. We classified the interactions and tested the interrater reliability, refined the framework, and agreed on the matrix of interactions. Results: We included 48 guidelines; two-thirds provided information about comorbidity. In total, we identified N = 247 interactions (on average, 14 per comorbidity): 68 were Di-Di-I, 115 were Di-D-I, 12 were DDI, and 52 were synergisms. All 18 comorbidities contributed at least one interaction. Conclusion: The interaction matrix provides a structure to present different types of interactions between an index disease and comorbidity. Guideline developers may consider the matrix to support clinical decision making in multimorbidity. Further research is needed to show its relevance to improve guidelines and health outcomes. (C) 2014 Elsevier Inc. All rights reserved

Systemic corticosteroids for acute sinusitis

BACKGROUND: Acute sinusitis is the inflammation and swelling of the nasal and paranasal mucous membranes and is a common reason for patients to seek primary care consultations. The related impairment of daily functioning and quality of life is attributable to symptoms such as facial pain and nasal congestion. OBJECTIVES: To assess the effects of systemic corticosteroids on clinical response rates and to determine adverse effects and relapse rates of systemic corticosteroids compared to placebo or standard clinical care in children and adults with acute sinusitis. SEARCH METHODS: We searched CENTRAL (2014, Issue 1), MEDLINE (1966 to February week 1, 2014) and EMBASE (January 2009 to February 2014). SELECTION CRITERIA: Randomised controlled trials (RCTs) comparing systemic corticosteroids to placebo or standard clinical care for patients with acute sinusitis. DATA COLLECTION AND ANALYSIS: Two review authors independently assessed the methodological quality of the trials and extracted data. MAIN RESULTS: Five RCTs with a total of 1193 adult participants met our inclusion criteria. We judged methodological quality to be moderate in four trials and high in one trial. Acute sinusitis was defined clinically in all trials. However, the three trials performed in ear, nose and throat (ENT) outpatient clinics also used radiological assessment as part of their inclusion criteria. All participants were assigned to either oral corticosteroids (prednisone 24 mg to 80 mg daily or betamethasone 1 mg daily) or the control treatment (placebo in four trials and non-steroidal anti-inflammatory drugs (NSAIDs) in one trial). In four trials antibiotics were prescribed in addition to oral corticosteroids or control treatment, while one trial investigated the effects of oral corticosteroids as a monotherapy.When combining data from the five trials, participants treated with oral corticosteroids were more likely to have short-term resolution or improvement of symptoms than those receiving the control treatment: at days three to seven (risk ratio (RR) 1.3, 95% confidence interval (CI) 1.1 to 1.6; risk difference (RD) 17%, 95% CI 6% to 29%) and at days four to 14 (RR 1.2, 95% CI 1.0 to 1.5; RD 14%, 95% CI 1% to 27%). A sensitivity analysis including the four trials with placebo as a control treatment showed similar results but with a lesser effect size: at days three to seven (RR 1.2, 95% CI 1.1 to 1.3; RD 11%, 95% CI 4% to 17%) and days four to 14 (RR 1.1, 95% CI 1.0 to 1.2; RD 8%, 95% CI 2% to 13%). Statistical heterogeneity was high for many analyses. Subgroup analyses revealed that corticosteroid monotherapy had no beneficial effects. Furthermore, scenario analysis showed that outcomes missing from the trial reports might have introduced attrition bias (a worst-case scenario showed no statistically significant beneficial effect of oral corticosteroids). No trial reported effects on relapse or recurrence rates. Reported side effects in patients treated with oral corticosteroids were mild (nausea, vomiting, gastric complaints) and did not significantly differ from those receiving placebo. AUTHORS' CONCLUSIONS: Oral corticosteroids as a monotherapy appear to be ineffective for adult patients with clinically diagnosed acute sinusitis. Current data on the use of oral corticosteroids as an adjunctive therapy to oral antibiotics are limited: almost all trials are performed in secondary care settings and there is a significant risk of bias. This limited evidence suggests that oral corticosteroids in combination with antibiotics may be modestly beneficial for short-term relief of symptoms in acute sinusitis, with a number needed to treat to benefit of seven for resolution or symptom improvement. A large primary care factorial trial is needed to establish whether oral corticosteroids offer additional benefits over antibiotics in acute sinusitis

A cardiovascular extension of the Health Measurement Questionnaire

OBJECTIVE: To investigate the psychometric properties of a cardiovascular extension of an existing utility-based quality of life questionnaire (Health Measurement Questionnaire). The new instrument has been named the Utility Based Quality of life--Heart questionnaire, or UBQ-H. DESIGN: Explored the test-retest reliability, construct validity, and responsiveness of the UBQ-H. PATIENTS: A sample of 322 patients attending cardiac outpatient clinics were recruited from two large metropolitan teaching hospitals. A second sample of 1112 patients taking part in the LIPID trial was also used to investigate the validity and responsiveness of the UBQ-H. RESULTS: Ninety per cent of all UBQ-H questionnaires were returned, and item completion rates were high (median of less than 1% missing or N/A answers). Cronbach's alpha measure of internal consistency for the scales ranged between 0.79- 0.91, and each item was also most strongly correlated with its hypothesised domain than alternative domains. The intra-class test- retest reliability of the UBQ-H scales ranged from 0.65 to 0.81 for patients with stable health. Results supported the construct validity of the UBQ-H. The UBQ-H was significantly correlated with other information on quality of life (for example, General Health Questionnaire) as anticipated. The instrument was able to distinguish between contrasted groups of patients (for example, with versus without symptoms of dyspnoea, prior myocardial infarction versus none, etc), and was responsive to changes in health associated with adverse events requiring hospitalisation. CONCLUSIONS: The modifications made to the Health Measurement Questionnaire has resulted in an assessment designed for cardiovascular patients that has proved to be both reliable and valid.