Quality of adverse event assessment in randomized controlled trials and observational studies.
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Diphosphonates↗
Biomedical subjects
Mark Helfand
Publications and source records attributed to Mark Helfand.
Screening for postmenopausal osteoporosis: a review of the evidence for the U.S. Preventive Services Task Force.
BACKGROUND: Although osteoporotic fractures present an enormous health burden, it is not clear whether screening to identify high-risk persons is appropriate. PURPOSE: To examine evidence on the benefits and harms of screening postmenopausal women for osteoporosis. DATA SOURCES: MEDLINE (1966 to May 2001), HealthSTAR (1975 to May 2001), and Cochrane databases; reference lists; and experts. STUDY SELECTION: English-language abstracts that included original data about postmenopausal women and osteoporosis and addressed the effectiveness of risk factor assessment, bone density tests, or treatment were included. DATA EXTRACTION: Selected information about patient population, interventions, clinical end points, and study design were extracted, and a set of criteria was applied to evaluate study quality. DATA SYNTHESIS: No trials of the effectiveness of screening have been published. Instruments developed to assess clinical risk factors for low bone density or fractures have moderate to high sensitivity and low specificity. Among different bone density tests measured at various sites, bone density measured at the femoral neck by dual-energy x-ray absorptiometry is the best predictor of hip fracture. Women with low bone density have approximately a 40% to 50% reduction in fracture risk when treated with bisphosphonates. CONCLUSIONS: Population screening would be based on evidence that the risk for osteoporosis and fractures increases with age, that the short-term risk for fracture can be estimated by bone density tests and risk factors, and that fracture risk can be reduced with treatment. The role of risk factor assessment and different bone density techniques, frequency of screening, and identification of subgroups for which screening is most effective remain unclear.
Aged↗
Breast cancer screening: a summary of the evidence for the U.S. Preventive Services Task Force.
PURPOSE: To synthesize new data on breast cancer screening for the U.S. Preventive Services Task Force. DATA SOURCES: MEDLINE; the Cochrane Controlled Trials Registry; and reference lists of reviews, editorials, and original studies. STUDY SELECTION: Eight randomized, controlled trials of mammography and 2 trials evaluating breast self-examination were included. One hundred fifty-four publications of the results of these trials, as well as selected articles about the test characteristics and harms associated with screening, were examined. DATA EXTRACTION: Predefined criteria were used to assess the quality of each study. Meta-analyses using a Bayesian random-effects model were conducted to provide summary relative risk estimates and credible intervals (CrIs) for the effectiveness of screening with mammography in reducing death from breast cancer. DATA SYNTHESIS: For studies of fair quality or better, the summary relative risk was 0.84 (95% CrI, 0.77 to 0.91) and the number needed to screen to prevent one death from breast cancer after approximately 14 years of observation was 1224 (CrI, 665 to 2564). Among women younger than 50 years of age, the summary relative risk associated with mammography was 0.85 (CrI, 0.73 to 0.99) and the number needed to screen to prevent one death from breast cancer after 14 years of observation was 1792 (CrI, 764 to 10 540). For clinical breast examination and breast self-examination, evidence from randomized trials is inconclusive. CONCLUSIONS: In the randomized, controlled trials, mammography reduced breast cancer mortality rates among women 40 to 74 years of age. Greater absolute risk reduction was seen among older women. Because these results incorporate several rounds of screening, the actual number of mammograms needed to prevent one death from breast cancer is higher. In addition, each screening has associated risks and costs.
Adult↗
Subclinical hyperthyroidism detected by screening: look before you treat.
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Humans↗
A systematic review of the efficacy of telemedicine for making diagnostic and management decisions.
We conducted a systematic review of the literature to evaluate the efficacy of telemedicine for making diagnostic and management decisions in three classes of application: office/hospital-based, store-and-forward, and home-based telemedicine. We searched the MEDLINE, EMBASE, CINAHL and HealthSTAR databases and printed resources, and interviewed investigators in the field. We excluded studies where the service did not historically require face-to-face encounters (e.g. radiology or pathology diagnosis). A total of 58 articles met the inclusion criteria. The articles were summarized and graded for the quality and direction of the evidence. There were very few high-quality studies. The strongest evidence for the efficacy of telemedicine for diagnostic and management decisions came from the specialties of psychiatry and dermatology. There was also reasonable evidence that general medical history and physical examinations performed via telemedicine had relatively good sensitivity and specificity. Other specialties in which some evidence for efficacy existed were cardiology and certain areas of ophthalmology. Despite the widespread use of telemedicine in most major medical specialties, there is strong evidence in only a few of them that the diagnostic and management decisions provided by telemedicine are comparable to face-to-face care.
Decision Making↗
Projected cost-effectiveness of statewide universal newborn hearing screening.
OBJECTIVES: Early identification of hearing impairment may improve language outcomes and subsequent school and occupational performance of the deaf. Universal newborn hearing screening (UNHS), currently mandated by 32 states, can reduce the median age of identification of hearing impairment from 12 to 18 months to 6 months or less. However, because false-negative tests must be minimized, the prevalence of congenital deafness is low, and screening tests are imperfect, UNHS results in many false-positive results and has a low positive predictive value (PPV). The objective of this study was to evaluate UNHS and selective screening in terms of both short- and long-term benefits, harms, and financial costs and to identify steps in the screening process that could be improved to increase cost-effectiveness. METHODS: The cost-effectiveness analysis, conducted from the societal perspective, compared the projected outcomes of 1) no newborn hearing screening, 2) selective newborn hearing screening, and 3) UNHS for a hypothetical state birth cohort of 80 000 infants. Probability and cost estimates for the decision model were obtained from published studies, expert opinion, and national and state sources. The main outcomes were incremental cost per infant whose deafness was diagnosed by 6 months, which included only the cost of screening and diagnostic evaluation; and incremental cost per deaf child with normal language, which also included the costs of medical care, education and assistive devices, and lost productivity over the lifetime of the deaf individual. RESULTS: Selective screening identified 62 of the 128 deaf infants in the birth cohort, referred 0.18% of all infants for diagnostic evaluation, and had a PPV of 43%. UNHS identified 116 of the 128 deaf infants, referred 1.6% of all infants, and had a PPV of 8.8%. Our model simulated real-world conditions in which some infants whose deafness is identified at screening do not receive a definitive diagnosis of being deaf before 6 months; and a portion of deaf and hard-of-hearing infants who 1) have false-negative screening test results, 2) are not screened, or 3) fail the hearing screen but are not immediately followed up with diagnostic evaluation nonetheless receive a diagnosis by 6 months of age. In the absence of newborn hearing screening, approximately 30 deaf infants were identified by 6 months of age by passive detection alone at a cost of $69 000. The selective screening protocol, when compared with no newborn hearing screening, resulted in an additional 36 infants whose deafness was diagnosed by 6 months at an additional cost of approximately $600 000, yielding an incremental cost-effectiveness of approximately $16 000 per additional infant whose deafness was diagnosed by 6 months. Compared with selective screening, the UNHS protocol resulted in 33 additional infants whose deafness was diagnosed by 6 months of age at an additional cost of approximately $1.5 million, yielding an incremental cost-effectiveness of approximately $44 000 per additional infant whose deafness was diagnosed by 6 months of age. Increasing the rate of follow-up to diagnostic evaluation from the base-case estimate of 77% to 100% decreased the incremental cost of UNHS to $38 000 per additional infant whose deafness was diagnosed by 6 months. Under the base-case assumptions about lifetime savings that result from normal language with early intervention, UNHS resulted in normal language achievement for more deaf children and was cost saving in the long term compared with both selective screening and no screening. CONCLUSIONS: The short-term cost-effectiveness of UNHS is comparable to the cost per case diagnosed of other newborn screening programs and could be improved by increasing the rate of follow-up to diagnostic evaluation after positive screening test results. If early identification results in improved language abilities, lower educational and vocational costs, and increased lifetime productivity, then UNHS has the potential for long-term cost savings compared with selective hearing screening and no screening. To understand the actual long-term economic effects of UNHS, better evidence is needed regarding the impact of early intervention on language outcomes and subsequent changes in educational costs and lifetime productivity.
Cohort Studies↗
A look back...and ahead.
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Attitude of Health Personnel↗
The effectiveness of primary care-based interventions to promote breastfeeding: systematic evidence review and meta-analysis for the US Preventive Services Task Force.
PURPOSE: We wanted to systematically review whether primary care-based interventions improve initiation and duration of breastfeeding. METHODS: Studies were found by searching MEDLINE (1966-2001), Health-STAR, the Cochrane Database of Systematic Reviews, the National Health Service Centre for Reviews and Dissemination Databases, and bibliographies of identified trials and review articles. Studies were included if they originated in the primary care setting and were conducted in a developed country, written in English, and contained a concurrent control group. RESULTS: Thirty randomized and nonrandomized controlled trials and 5 systematic reviews of breastfeeding counseling were included. Educational programs had the greatest effect of any single intervention on both initiation (difference 0.23; 95% confidence interval [CI], 0.12-0.34) and short-term duration (difference 0.39; 95% CI, 0.27-0.50). Support programs conducted by telephone, in person, or both increased short-term (difference 0.11; 95% CI, 0.03-0.19) and long-term duration (difference 0.08; 95% CI, 0.02-0.16). In contrast, written materials such as pamphlets did not significantly increase breastfeeding. Data were insufficient to determine whether the combination of education with support was more effective than education alone. CONCLUSIONS: Educational programs were the most effective single intervention. One woman would breast-feed for up to 3 months for every 3 to 5 women attending breastfeeding educational programs. Future research and policy should focus on translating these findings into more widespread practice in diverse primary care settings.
Advisory Committees↗
Using evidence reports: progress and challenges in evidence-based decision making.
This Perspective describes the advantages of using systematic evidence reviews in preferred drug deliberations. By involving decisionmakers in defining the scope, evidence reports help focus deliberations on clinically important questions and reduce the likelihood of bias. They define the limits of the evidence and the magnitude of differences among compared drugs; however, decisionmakers must consider other factors and apply their values to their decisions in an explicit, defensible manner. GRADE, an international consortium of systematic-review developers and users, is seeking to improve the process of incorporating considerations other than the strength of evidence in making decisions that are evidence based.
Decision Making, Organizational↗