Dipyridamole in the treatment of angina pectoris: a meta-analysis

A meta-analysis was performed to reevaluate the efficacy of dipyridamole for prophylaxis of angina pectoris. We found 10 articles that reported 11 randomized control trials published between 1960 and 1970. Three trials found a statistically significant benefit for the drug vs placebo, four showed a positive trend, two found no difference, and two showed a slight trend favoring placebo. When the results of all 11 trials were combined, two different statistical methods showed a statistically significant benefit from the drug. These combined results must be interpreted cautiously because of excluded patients and other methodologic variations in the studies, as well as evidence from other studies that dipyridamole may aggravate angina. Nevertheless, we conclude that there is some evidence for efficacy of the drug and believe the question should be restudied in larger and better-designed trials.

Meta-analyses of randomized controlled trials

A new type of research, termed meta-analysis, attempts to analyze and combine the results of previous reports. We found 86 meta-analyses of reports of randomized controlled trials in the English-language literature. We evaluated the quality of these meta-analyses, using a scoring method that considered 23 items in six major areas--study design, combinability, control of bias, statistical analysis, sensitivity analysis, and application of results. Only 24 meta-analyses (28 percent) addressed all six areas, 31 (36 percent) addressed five, 25 (29 percent) addressed four, 5 (6 percent) addressed three, and 1 (1 percent) addressed two. Of the 23 individual items, between 1 and 14 were addressed satisfactorily (mean +/- SD, 7.7 +/- 2.7). We conclude that an urgent need exists for improved methods in literature searching, quality evaluation of trials, and synthesizing of the results.

An analysis of the costs of ambulatory and inpatient care

Savings resulting from the substitution of ambulatory for inpatient care have been widely reported. This study examined the hypothesis that these savings may result from a reduction of services provided to the ambulatory patient and/or from an incomplete evaluation of these services, when the market value of relatives' support services is not included. Cataract extraction was chosen as an example. Sixty-two medical records of patients admitted to Mount Sinai for cataract extraction in the first six months of 1980 were reviewed, and the cost of their stay was estimated. This cost was then compared to five simulations of home care costs. The simulations differed among themselves primarily as to the experience and training of the person providing nursing services--from an RN to an untrained relative. The quantity and type of service provided to inpatients were assumed to be provided to ambulatory patients in all five simulations. The results of the comparison of hospital costs to home costs were that, in the case of post-cataract extraction, home care is less costly than hospital care either if fewer services are provided to home patients or if the cost of some services assumed by relatives is not calculated.