Benjamin Littenberg

Outcomes after displaced fractures of the femoral neck. A meta-analysis of one hundred and six published reports.

Methods of meta-analysis, a technique for the combination of data from multiple sources, were applied to analyze 106 reports of the treatment of displaced fractures of the femoral neck. Two years or less after primary internal fixation of a displaced fracture of the femoral neck, a non-union had developed in 33 per cent of the patients and avascular necrosis, in 16 per cent. The rate of performance of a second operation within two years ranged from 20 to 36 per cent after internal fixation and from 6 to 18 per cent after hemiarthroplasty (relative risk, 2.6; 95 per cent confidence interval, 1.4 to 4.6). Conversion to an arthroplasty was the most common reoperation after internal fixation and accounted for about two-thirds of these procedures. The remaining one-third of the reoperations were for removal of the implant or revision of the internal fixation. For the patients who had had a hemiarthroplasty, the most common reoperations were conversion to a total hip replacement, removal or revision of the prosthesis, and debridement of the wound. Although we observed an increase in the rate of mortality at thirty days after primary hemiarthroplasty compared with that after primary internal fixation, the difference was not significant (p = 0.22) and did not persist beyond three months. The absolute difference in perioperative mortality between the two groups was small. An anterior operative approach for arthroplasty consistently was associated with a lower rate of mortality at two months than was a posterior approach. Some reports showed promising results after total hip replacement for displaced fractures of the femoral neck; however, randomized clinical trials are still needed to establish the value of this treatment.

Estimating Diagnostic Accuracy from Multiple Conflicting Reports A New Meta-analytic Method

Reports of diagnostic accuracy often differ. The authors present a method to summarize disparate reports that uses a logistic transformation and linear regression to produce a summary receiver operating characteristic curve. The curve is useful for summarizing a body of diagnostic accuracy literature, comparing technologies, detecting outliers, and finding the optimum operating point of the test. Examples from clinical chemistry and diagnostic radiology are provided. By extending the logic of meta-analysis to diagnostic testing, the method provides a new tool for technology assessment. Key words: meta-analysis; sensitivity and specificity; decision support; data interpretation, statistical; regression analysis; diagnostic accuracy. (Med Decis Making 1993;13:313-321)

Outcome among surviving very low birthweight infants: a meta-analysis.

Because published outcome studies are the only available source of data about the morbidity among surviving very low birthweight infants (VLBW, less than 1500 g) a search was carried out of 1136 references in the English language. A total of 111 outcome studies were found that reported morbidity data in cohorts of VLBW infants born since 1960. The methods used and results obtained in these studies were systematically assessed. No agreement exists about the definition of study populations, descriptive statistics, or measurement of outcome. Follow up ranged from six months to 14 years. In 85 cohorts the incidence of cerebral palsy was recorded, and in 106 that of disability. Studies that followed up infants for longer time periods reported higher incidences of disability. Studies from the United States reported higher incidences of disability than those from other countries. The median incidence of cerebral palsy among all the cohorts studied was 7.7%, and the median incidence of disability was 25.0%. Despite substantial improvements in the mortality of VLBW infants, poor outcomes among survivors are common.

The Single Item Literacy Screener: Evaluation of a brief instrument to identify limited reading ability

BackgroundReading skills are important for accessing health information, using health care services, managing ones health and achieving desirable health outcomes. Our objective was to assess the diagnostic accuracy of the Single Item Literacy Screener (SILS) to identify limited reading ability, one component of health literacy, as measured by the S-TOFHLA.MethodsCross-sectional interview with 999 adults with diabetes residing in Vermont and bordering states. Participants were randomly recruited from Primary Care practices in the Vermont Diabetes Information System June 2003 – December 2004. The main outcome was limited reading ability. The primary predictor was the SILS.ResultsOf the 999 persons screened, 169 (17%) had limited reading ability. The sensitivity of the SILS in detecting limited reading ability was 54% [95% CI: 47%, 61%] and the specificity was 83% [95% CI: 81%, 86%] with an area under the Receiver Operating Characteristics Curve (ROC) of 0.73 [95% CI: 0.69, 0.78]. Seven hundred seventy (77%) screened negative on the SILS and 692 of these subjects had adequate reading skills (negative predictive value = 0.90 [95% CI: 0.88, 0.92]). Of the 229 who scored positive on the SILS, 92 had limited reading ability (positive predictive value = 0.4 [95% CI: 0.34, 0.47]).ConclusionThe SILS is a simple instrument designed to identify patients with limited reading ability who need help reading health-related materials. The SILS performs moderately well at ruling out limited reading ability in adults and allows providers to target additional assessment of health literacy skills to those most in need. Further study of the use of the SILS in clinical settings and with more diverse populations is warranted.

The cost‐effectiveness of preoperative autologous blood donation for total hip and knee replacement

Although the frequency of preoperative autologous blood donation is increasing dramatically, the economic implications of its use remain largely unexplored. Decision analysis was used to calculate the cost‐ effectiveness of autologous blood donation for hip and knee replacement. Cost‐effectiveness, expressed as cost per quality‐adjusted year of life saved, was based on observed red cell use in 629 patients undergoing surgery at two tertiary‐care centers. Autologous blood donation for bilateral and revision joint replacement cost

Improving physician compliance with preventive medicine guidelines.

40,000 per quality‐adjusted year of life saved at Center 1 and

A Controlled Trial of Methylprednisolone in the Emergency Treatment of Acute Asthma

241,000 at Center 2. Autologous blood donation for primary unilateral hip replacement cost

Screening for Hypertension

373,000 per quality‐adjusted year of life saved at Center 1 and

A Meta-analytic Method for Summarizing Diagnostic Test Performances Receiver-operating-characteristic - summary Point Estimates

740,000 at Center 2. Autologous blood donation was least cost‐ effective for primary unilateral knee replacement (

Cost-effectiveness of preoperative autologons donation in coronary artery bypass grafting

1,147,000/quality‐ adjusted year of life saved at Center 1 and