Are nonspecific practice guidelines potentially harmful? A randomized comparison of the effect of nonspecific versus specific guidelines on physician decision making.

OBJECTIVE: To test the ability of two different clinical practice guideline formats to influence physician ordering of electrodiagnostic tests in low back pain. DATA SOURCES/STUDY DESIGN: Randomized controlled trial of the effect of practice guidelines on self-reported physician test ordering behavior in response to a series of 12 clinical vignettes. Data came from a national random sample of 900 U.S. neurologists, physical medicine physicians, and general internists. INTERVENTION: Two different versions of a practice guideline for the use of electrodiagnostic tests (EDT) were developed by the U.S. Agency for Health Care Policy and Research Low Back Problems Panel. The two guidelines were similar in content but varied in the specificity of their recommendations. DATA COLLECTION: The proportion of clinical vignettes for which EDTs were ordered for appropriate and inappropriate clinical indications in each of three physician groups were randomly assigned to receive vignettes alone, vignettes plus the nonspecific version of the guideline, or vignettes plus the specific version of the guideline. PRINCIPAL FINDINGS: The response rate to the survey was 71 percent. The proportion of appropriate vignettes for which EDTs were ordered averaged 77 percent for the no guideline group, 71 percent for the nonspecific guideline group, and 79 percent for the specific guideline group (p = .002). The corresponding values for the number of EDTs ordered for inappropriate vignettes were 32 percent, 32 percent, and 26 percent, respectively (p = .08). Pairwise comparisons showed that physicians receiving the nonspecific guidelines ordered fewer EDTs for appropriate clinical vignettes than did physicians receiving no guidelines (p = .02). Furthermore, compared to physicians receiving nonspecific guidelines, physicians receiving specific guidelines ordered significantly more EDTs for appropriate vignettes (p = .0007) and significantly fewer EDTs for inappropriate vignettes (p = .04). CONCLUSIONS: The clarity and clinical applicability of a guideline may be important attributes that contribute to the effects of practice guidelines.

Is the quality of diabetes care better in a diabetes clinic or in a general medicine clinic?

OBJECTIVE: To compare the quality of ambulatory diabetes care delivered by physicians in the diabetes clinic versus the general medicine clinic of a university-affiliated Veterans Administration medical center. RESEARCH DESIGN AND METHODS: This is a retrospective study that involved the review of medical records against predetermined process-of-care criteria. A total of 112 patients with diabetes were randomly selected, of whom 56 were cared for in the general medicine clinic and 56 in the diabetes clinic. The following main outcome measures were examined: 1) the compliance with individual criteria; and 2) the proportion of patient visits in each clinic receiving minimally acceptable quality, defined as a blood pressure measurement, a record of type of hypoglycemic medication, a glycated hemoglobin measurement within the past year, a urinalysis within the past year, an ophthalmologist or optometrist eye examination within the past year or scheduled in the next six months, a record of change in therapeutic management, and a scheduled return visit. RESULTS: The diabetes clinic performed significantly better than the general medicine clinic on the following criteria: a record of a patient's self-monitoring of blood glucose levels; a foot examination; a comprehensive eye examination; a glycated hemoglobin measurement; and a referral for diabetic education. The proportion of patient visits meeting the minimally acceptable levels of quality was better in the diabetes clinic than the general medicine clinic (73 vs. 52%, P = 0.02). CONCLUSIONS: Patients cared for by physicians in the diabetes clinic receive better quality of diabetes care than do patients cared for by physicians in the general medical clinic. If patient care is to be shifted from specialists to generalists, additional attention needs to be paid to ensure that generalists have the knowledge and system resources necessary to deliver an acceptable quality of diabetes care.

Comparison of screening tests for non-insulin-dependent diabetes mellitus.

BACKGROUND: Screening for non-insulin-dependent diabetes mellitus (NIDDM) can be useful in clinical practice and in epidemiologic and genetic studies, but the available information for choosing between screening methods is limited. In this study, characteristics of several screening tests for NIDDM were compared. METHODS: Among Pima Indians participating in an epidemiologic study, the sensitivity and specificity for detecting NIDDM of fasting plasma glucose (FPG) levels and two measures of glycated hemoglobin (HbA1 or HbA1c) were compared in 2092 fasting subjects. Glycated hemoglobin, quantitative glycosuria, and dipstick glycosuria were compared in 237 nonfasting subjects. Diabetes was diagnosed using an oral glucose tolerance test if the 2-hour postload venous plasma glucose concentration was 11.1 mmol/L (200 mg/dL) or greater. The area under the relative operating characteristic curve was used to compare tests. RESULTS: In fasting subjects, the sensitivity for detecting diabetes with 98% specificity was 78.8% for HbA1 level of 7.5% or greater, 80.3% for HbA1c level of 6.3% or greater, and 88.0% for FPG level of 6.83 mmol/L (123 mg/dL) or greater. By relative operating characteristic analysis, there were no significant differences between FPG and HbA1c, but FPG was significantly more sensitive than HbA1. In nonfasting subjects the sensitivity at 98% specificity was 92.9% for HbA1 level of 7.3% or greater, 80.6% for quantitative urine glucose level of 1.94 mmol/L (35 mg/dL) or greater, and 64.3% for trace or greater of dipstick glycosuria. The area under the relative operating characteristic curve was significantly greater for glycated hemoglobin than for either measure of glycosuria. CONCLUSIONS: Although FPG has the best screening properties, HbA1c, HbA1, and quantitative urine glucose also provide high specificity and approximately 80% sensitivity in detecting NIDDM. The choice of a particular method could depend on cost, convenience, and availability.