Sensitivity meta-analysis

Cross-reactions with aspirin and NSAIDs are of practical importance. Typically, AIA patients are sensitive to all NSAIDs that preferentially inhibit COX-1 (table 2). Acetaminophen (paracetamol), a weak inhibitor of COX-1, is regarded as a relatively safe therapeutic alternative for almost all patients with AIA. High doses of the drug (>1,000 mg) have been reported to provoke mild, easily reversed bronchos-pasm in some AIA patients [13]. Some rare, well-documented cases of coexistence of aspirin and paracetamol sensitivity have been described. However, according to a recent meta-analysis, less that 2% of asthmatics are sensitive to both aspirin and paracetamol [14]. 

The analysis carried out by Schwartz (1994) included a total of eight studies, three longitudinal and five cross-sectional, relating blood lead to Full Scale IQ in school age children. To evaluate potential confounding, the baseline meta-analysis was followed by sensitivity analyses in order to contrast results... 

In a meta-analysis, Westreenen et at. analyzed 12 studies concerning the diagnostic accuracy of [ F]-FDG-PET in staging the locoregional lymph node status [75]. The pooled sensitivity and specificity of [ F]-FDG-PET in detecting locoregional lymph node involvement were 51% and 84%, respectively. 

Pollock, V. E. 1992. Meta-analysis of subjective sensitivity to alcohol in sons of alcoholics. American Journal of Psychiatry 149 1534-38. 

The maturity decision cutoff varies from 19,000 to 60,000/p.L. TypicaEy 35,000/p.L is used, " but this is affected strongly by the instrument used. AH clinical outcomes studies have reported that LBC has high sensitivity (95% to 100%) but low specificity (about 70%) for prediction of RDS. A recent meta-analysis reported that at a fixed sensitivity of 95%, the LBC specificity was 80%, whereas the L/S ratio specificity was 70%. 

Meta-analysis of more than 24,000 patients in 147 studies showed a mean sensitivity of 68% and specificity of 77% for ET as a diagnostic test. The specificity of ET to detect the presence of CAD, compared with angiography, is 84%. Sensitivity ranges from 40% to 90% depending on the number of vessels affected, with a mean of 66%. 

A recent meta-analysis showed that sensitivities for the detection of carotid and vertebral arterial dissection ranged from 50 to 100% and specificities ranged from 29 to 100% [63]. In the largest study comparing internal carotid and vertebral artery dissections with DSA, the conventional MR appearance alone had an estimated 84% sensitivity and 99% specificity for diagnosing ICA dissection, while 3D TOF MRA had a 95% sensitivity and 99% specihcity [64]. For vertebral artery dissections, MRI and MRA were less nsefnl MRI had sensitivity and specihcity for vertebral artery dissection of 60 and 58%, while 3D TOF MRA sensitivity was 20%, with 100% specihcity [64, 65]. 

Oral administration of thyroxine (T4) is the treatment of choice for all forms of hypothyroidism. Other thyroid hormone preparations, including desiccated thyroid and triiodothyronine (T3) alone, should not be used for treatment of patients with hypothyroidism (Levy, 1991). The absorption of T3 is very rapid, and high serum levels of T3 are reached rapidly. Furthermore, elderly persons are very sensitive to the effects of T3. A recent meta-analysis of controlled clinical trials has shown that there is no benefit of combined T3 and T4 therapy when compared with T4 therapy alone (Grozinsky-Glasberg et at, 2006). 

It may be necessary to ask patients directly for information (e.g., number and length of time of home visits by health professionals). Missing data can be estimated using meta-analysis to combine results from other studies. Alternatively assumptions can be based on expert opinion and then tested using sensitivity analysis. If data is collected from different sources then it will be important to use simulation models to combine the data and take account of the variation. 

The meta-analysis employed a prespecified analysis plan, which specified trial inclusion criteria, hypotheses, outcome definitions, analysis methods, sensitivity analyses, and subgroups. The trial inclusion criteria and the outcome definitions have already been discussed. The primary analysis method stratified by trial and accounted for the sparse nature of the outcome events by using exact statistical methods. The sensitivity analysis examined the possibility and consequences of the following differential exposure time between the randomized treatment arms, heterogeneity of the effect measure across the trials, and trials with no events (FDA 2006). The patient-level data allowed for the examination of important subgroups, including patient age, and for the examination of changing risk over time. 

Patsopoulos NA, Evangelou E, loarmidis JP. Sensitivity of between-study heterogeneity in meta-analysis Proposed metrics and empirical evaluation. International Journal of Epidemiology, 37 1148-1157,2008. 

The abnormal thickening of bowel walls is the most widely and commonly US finding reported in the literature to diagnose CD. In a recent meta-analysis aiming at evaluating the impact of different cut-off values of bowel wall thickening (3 nun vs 4 nun) in determining the presence of CD, Fraquelli et aL (2005) showed that when a >3-mm cut-off level was observed for abnormality, sensitivity and specificity were 88% and 93%, respectively, whilst when a cut-off level of >4 mm was used, sensitivity was 75% and specificity 97%. 

A meta-analysis of 32 pubhcations of nerve-conduction studies and occupational lead exposure foimd BLL to be a weak predictor of peripheral nerve impairment (Davis and Svendsgaard 1990). Nerve-conduction testing includes analysis of latent period (time it takes for stimulatory impulse to initiate an evoked potential), conduction velocity, and amplitude. Reduced nerve-conduction velocities in lead-exposed subjects revealed that the median motor nerve was most sensitive. 

In the field of breast cancer, RNA expression profiles have been derived that achieve similar sensitivity but are more specific than are conventional algorithms in predicting distant metastasis, that is, less error-prone in recommending adjuvant systemic therapy. Meta-analysis of different prognostic RNA signatures revealed that genes associated with cell proliferation provide the driving force in all of them. 

Whether or not to include trials with no cardiovascular events in a meta-analysis has been a highly debated topic. If a trial had a sufficiently long period of follow-up and no cardiovascular events were reported, these data would appear to support the hypothesis of noninferiority however, no formal statistical method exists for estimating the cardiovascular risk from such data, and they are typically excluded from the analysis. Tian and colleagues (2009) discussed a method of obtaining an exact confidence interval for the difference in event rates at a fixed time point that permits combining data from trials that have zero events with data from other trials. This method could be utilized as a supportive sensitivity analysis. 

In a recently published meta-analysis (Hamon et al. 2007), the pooled diagnostic performance for the detection of significant stenoses of the coronary artery tree improved with 64-slice CT when compared with 16-slice CT. This was the case with regard to the sensitivity on a per-segment based analysis. The highest improvement with 64-slice CT when compared with 16-slice CT was the significant increase in specificity from 69 to 90% and the increase in the positive predictive value from 79 to 93%. Thus, 64-slice CT performs more accurately as compared with 16-slice CT in the determination of healthy individuals. 

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