ABSTRACT: Case-control studies are a common and efficient means of studying rare diseases or illnesses with long latency periods. Matching of cases and controls is frequently employed to control the effects of known potential confounding variables. The analysis of matched data requires specific statistical methods.
The objective of this study was to determine the proportion of published, peer-reviewed matched case-control studies that used statistical methods appropriate for matched data. Using a comprehensive set of search criteria we identified 37 matched case-control studies for detailed analysis.
Among these 37 articles, only 16 studies were analyzed with proper statistical techniques (43%). Studies that were properly analyzed were more likely to have included case patients with cancer and cardiovascular disease compared to those that did not use proper statistics (10/16 or 63%, versus 5/21 or 24%, P = 0.02). They were also more likely to have matched multiple controls for each case (14/16 or 88%, versus 13/21 or 62%, P = 0.08). In addition, studies with properly analyzed data were more likely to have been published in a journal with an impact factor listed in the top 100 according to the Journal Citation Reports index (12/16 or 69%, versus 1/21 or 5%, P ≤ 0.0001).
The findings of this study raise concern that the majority of matched case-control studies report results that are derived from improper statistical analyses. This may lead to errors in estimating the relationship between a disease and exposure, as well as the incorrect adaptation of emerging medical literature.
Clinical Epidemiology 01/2012; 4:99-110.
Critical care medicine 03/2011; 39(3):610-1; author reply 611. · 6.37 Impact Factor
ABSTRACT: Critically ill patients are frequently managed with invasive technologies as part of their medical care. Little is known about use patterns. We examined use trends for invasive technologies used in critically ill patients.
Using time series analysis and data on 26 989 patients from 3 medical-surgical intensive care units (ICUs) (n = 18 224) and 1 surgical ICU (n = 8765) between January 1, 1999, and January 1, 2007, we measured changes in the proportion of patients receiving the 4 most frequently used invasive technologies used in critically ill patients.
The 4 most common invasive technologies used in critically ill patients during the study period were arterial lines (71%), endotracheal intubations (61%), central venous catheters (51%), and pulmonary artery catheters (18%). The proportion of ICU patients who received pulmonary artery catheters decreased from 25% in 1999 to 8% in 2006 (P < .001). Use of central venous catheters increased from 39% to 46% (P < .001). After adjusting for baseline characteristics, patients admitted in 2006 were 4 times less likely to receive a pulmonary artery catheter (odds ratio, 0.28; 95% confidence interval, 0.24-0.33), but 42% (odds ratio, 1.42; 95% confidence interval, 1.27-1.58) more likely to receive a central venous catheter than patients admitted in 1999. No significant changes were observed for intubations and arterial lines.
The use of invasive technologies in critically ill patients is changing and may have important implications for resource use, clinician education, and patient care. Initiatives should be considered for ensuring clinician competency during technology transitions.
Journal of critical care 02/2009; 24(3):471.e9-14. · 2.13 Impact Factor
ABSTRACT: To appraise the literature on the effect of initial renal replacement therapy (RRT) modality on clinical outcomes.
Systematic review and meta-analysis.
Academic medical center.
Adult critically ill patients with acute kidney injury.
Continuous vs. intermittent RRT.
MEDLINE, EMBASE, Cochrane Controlled Clinical Trials Register, and other sources were searched. We identified nine unique randomized trials (n = 1,403). No trial satisfied all quality indicators and several had limitations related to selection bias, randomization, imbalances in patient characteristics, and high treatment crossover. No trial standardized the timing, criteria, for initiation or dose of RRT. There was no statistical evidence that initial modality influenced mortality (odds ratio, 0.99; 95% confidence interval, 0.78-1.26, p = .93; I2 = 11%; nine trials, n = 1,403) or recovery to RRT independence (odds ratio, 0.76; 95% confidence interval, 0.28-2.07, p = .59; I2 = 0%; four trials, n = 306). There was suggestion that continuous RRT had fewer episodes of hemodynamic instability and better control of fluid balance.
We identified numerous issues related to study design, conduct, and quality that dispute the validity and question any inferences that can be drawn from these trials. In the context of these limitations, the initial RRT modality did not seem to affect mortality or recovery to RRT independence. There is urgent need for additional high-quality and suitably powered trials to adequately address this issue.
Critical care medicine 03/2008; 36(2):610-7. · 6.37 Impact Factor
ABSTRACT: Refractory status epilepticus (RSE) secondary to traumatic brain injury (TBI) may be under-recognized and is associated with significant morbidity and mortality.
This case report describes a 20 year old previously healthy woman who suffered a severe TBI as a result of a motor vehicle collision and subsequently developed RSE. Pharmacological coma, physiological support and continuous electroencephalography (cEEG) were undertaken.
Following 25 days of pharmacological coma, electrographic and clinical seizures subsided and the patient has made an excellent cognitive recovery.
With early identification, aggressive physiological support, appropriate monitoring, including cEEG, and an adequate length of treatment, young trauma patients with no previous seizure history and limited structural damage to the brain can have excellent neurological recovery from prolonged RSE.
Critical care (London, England) 02/2005; 9(6):R725-8. · 4.61 Impact Factor