PubMed Health⌕ Search

Biomedical subjects

Joseph Bernstein

Publications and source records attributed to Joseph Bernstein.

13 recordsLinked to original sources
PubMed2003

Statistical sampling and hypothesis testing in orthopaedic research.

The purpose of the current article was to review the process of hypothesis testing and statistical sampling and empower readers to critically appraise the literature. When the p value of a study lies above the alpha threshold, the results are said to be not statistically significant. It is possible, however, that real differences do exist, but the study was insufficiently powerful to detect them. In that case, the conclusion that two groups are equivalent is wrong. The probability of this mistake, the Type II error, is given by the beta statistic. The complement of beta, or 1-beta, representing the chance of avoiding a Type II error, is termed the statistical power of the study. We previously examined the statistical power and sample size in all of the studies published in 1997 in the American and British volumes of the Journal of Bone and Joint Surgery, and in Clinical Orthopaedics and Related Research. In the journals examined, only 3% of studies had adequate statistical power to detect a small effect size in this sample. In addition, a study examining only randomized control trials in these journals showed that none of 25 randomized control trials had adequate statistical power to detect a small effect size. However, beta, or power, is less well understood. Because of this, researchers and readers should be aware of the need to address issues of statistical power before a study begins and be cautious of studies that conclude that no difference exists between groups.

Epidemiologic Research Design↗
PubMed2003

Curricular reform in musculoskeletal medicine: needs, opportunities, and solutions.

Musculoskeletal medicine is not taught adequately in American medical schools and the predictable consequences are seen. Students cannot show cognitive mastery of the subject and lack confidence in this topic. To address this, the Academic Orthopaedic Society held a symposium on medical school education at its annual meeting in 2001. There, the panelists presented an analysis of the problem and proposed solutions. Specifically, it was noted that because of the autonomy of the various schools and their varied approaches to teaching, it would be unlikely that one monolithic and mandated plan could be effective on a national basis. Rather, successful reform would comprise a coalition-based effort to define learning objectives, to provide teaching materials, and to create forums for sharing resources. Recruitment of national organizations was thought to be essential. Finally, it was felt that although inadequate education is neither new nor necessarily unique among disciplines, the coming year or two, the beginning of the Bone and Joint decade, was seen to be a particularly auspicious time for attempting curricular reform.

Curriculum↗
PubMed2003

The incidence of pathology detected by magnetic resonance imaging of the knee: differences based on the specialty of the requesting physician.

The usage patterns of magnetic resonance imaging (MRI) by orthopedic and nonorthopedic surgeons were studied. A sample consisting of the radiologist reports from all knee MRIs in a single year at our institution were reviewed. Studies to evaluate tumors or infections were excluded. Reports were classified as normal or demonstrating degenerative joint disease, meniscal tears, cruciate ligament pathology, collateral ligament pathology, focal chondral defects, chondromalacia patella, cysts, extensor mechanism dysfunction, intraosseous edema, or fractures. Six hundred eighteen reports were reviewed. The combined incidence of a normal study or one that found only degenerative joint disease was 45% for nonorthopedic surgeons and 27.6% for orthopedic surgeons (P<.00001). Given the higher incidence of normal findings in studies ordered by nonorthopedic surgeons, these physicians probably use MRI more for screening whereas orthopedic surgeons are more apt to use it for confirmation. Therefore, if clinical guidelines for using MRI are to be established, differences in use as a function of specialty must be acknowledged.

Hospitals, University↗
PubMed2003

A perspective on the study of Moseley et al: questioning the value of arthroscopic knee surgery for osteoarthritis.

Arthroscopy for degenerative conditions of the knee is among the most commonly employed orthopedic procedures, but its effectiveness (like the effectiveness of many surgical operations) has never been proven in prospective trials. Moreover, the precise mechanism by which arthroscopy improves the course of degenerative conditions of the knee has not been established conclusively. Moseley et al performed a double-blinded, randomized, placebo-controlled trial to compare the effectiveness of arthroscopic lavage and arthroscopic debridement vs a sham procedure. Data regarding pain and function were obtained at multiple time points over a 2-year period. The authors found that all three treatment groups fared equally: each reported subjective symptomatic relief, but no objective improvement in function was noted in any of the groups. These data suggest that the benefits of arthroscopy for the treatment of osteoarthritis of the knee is to provide subjective pain relief, and that the means by which arthroscopy provides this benefit is via a placebo effect.

Arthroscopy↗
PubMed2002

Preoperative sedation in pediatric patients with sleep-disordered breathing.

OBJECTIVE: Based on a few reports that describe obstructive sleep apnea (OSA) patients as having an increased risk of acute upper airway obstruction (UAO) after pharmacological sedation, this population is less likely to receive sedation prior to surgery. Our objective was to evaluate pediatric patients with sleep-disordered breathing who received preoperative sedation to determine if there was an increase in preoperative airway obstruction. DESIGN: Retrospective chart review from 1995 to 2000. SETTING: Two tertiary care academic medical centers. PATIENTS: Sixty-five children (mean age=4.7+/-2.3 years; 49 boys, 16 girls) diagnosed with sleep-disordered breathing by sleep study or clinical evaluation that received preoperative midazolam hydrochloride. OUTCOME MEASURE: The occurrence of preoperative adverse events defined as UAO, hypoventilation, desaturation, bradycardia, or sustained lethargy that required active intervention after the administration of midazolam hydrochloride within 24 h of surgery. RESULTS: None of the 65 children evaluated in this study experienced respiratory compromise requiring intervention after the administration of preoperative sedation. Potential risk factors such as patients' age, sex, weight, comorbidities, midazolam hydrochloride dose, and severity of sleep apnea did not appear to affect outcome. CONCLUSION: The preliminary data suggested that preoperative sedation might be safely administered to children with mild or moderate sleep-disordered breathing, and possibly to children with severe OSA, if children are closely observed prior to surgery. Further prospective studies are needed to confirm these results.

Academic Medical Centers↗
PubMed2002

Educational deficiencies in musculoskeletal medicine.

BACKGROUND: We previously reported the results of a study in which a basic competency examination in musculoskeletal medicine was administered to a group of recent medical school graduates. This examination was validated by 124 orthopaedic program directors, and a passing grade of 73.1% was established. According to that criterion, 82% of the examinees failed to demonstrate basic competency in musculoskeletal medicine. It was suggested that perhaps a different passing grade would have been set by program directors of internal medicine departments. To test that hypothesis, and to determine whether the importance of the individual questions would be rated similarly, the validation process was repeated with program directors of internal medicine residency departments as subjects. METHODS: Our basic competency examination was sent to all 417 program directors of internal medicine departments in the United States. Each recipient was mailed a letter of introduction explaining the purpose of the study, a copy of the examination, and our answer key and scoring guide. There was no mention of the results of the first study. The subjects were requested to rate the importance of each question on the same visual analog scale, ranging from "not important" to "very important," as had been used by the orthopaedic program directors. These ratings were converted into numerical scores. The program directors were also asked to suggest a passing score for the examination, and this score was used to assess the examinees' performance on the examination. The results on the basis of the internal medicine program directors' responses and those according to the orthopaedic program directors' responses were compared. RESULTS: Two hundred and forty (58%) of the 417 program directors of internal medicine residency departments responded. They suggested a mean passing score (and standard deviation) of 70.0% +/- 9.9%. As reported previously, the mean test score of the eighty-five examinees was 59.6%. Sixty-six (78%) of them failed to demonstrate basic competency on the examination according to the criterion set by the internal medicine program directors. The internal medicine program directors assigned a mean importance score of 7.4 (of 10) to the questions on the examination compared with a mean score of 7.0 assigned by the orthopaedic program directors. The internal medicine program directors gave twenty-four of the twenty-five questions an importance score of at least 5 and seventeen of the twenty-five questions an importance score of at least 6.6. CONCLUSIONS: According to the standard suggested by the program directors of internal medicine residency departments, a large majority of the examinees once again failed to demonstrate basic competency in musculoskeletal medicine on the examination. It is therefore reasonable to conclude that medical school preparation in musculoskeletal medicine is inadequate.

Education, Medical, Graduate↗