Factors associated with implementation of preventive care measures in patients with diabetes mellitus.

BACKGROUND: There is only limited information on the extent to which physicians' characteristics affect the level of care and implementation of guidelines in patients with diabetes mellitus. OBJECTIVE: To identify physician characteristics associated with implementation of measures for preventive care in patients with diabetes mellitus and the distribution of implementation of these measures among them. PATIENTS AND METHODS: A retrospective chart audit of 519 patients eligible for health maintenance organization insurance on December 31, 1994, representing patients with diabetes receiving care from 22 primary care physician-providers of a managed care medical group in suburban North Los Angeles, Calif, and seen by physicians between January 1993 and December 1994. A short retroactive questionnaire for participating physicians was also used. The outcome measures were (1) measurement of serum high-density lipoprotein cholesterol; (2) urinalysis for the detection of proteinuria; and (3) ophthalmology referral for dilated fundus examination. RESULTS: Over a period of 2 years 78% of the patients had a high-density lipoprotein cholesterol determination, 80% had a test for proteinuria, and 62% were referred to an ophthalmologist. After adjustment for patient pool differences, physicians who were perceived by the administration of the medical group as "fast," based on a blinded evaluation of their number of patient encounters per unit time, had an odds ratio of 0.60 (95% confidence interval [CI], 0.37-0.95; P=.03) to obtain a high-density lipoprotein cholesterol determination in their patients and an odds ratio of 0.53 (95% CI, 0.32-0.87; P=.01) to test their patients for proteinuria. In patients requiring insulin, of fast physicians, the odds ratio for a referral for ophthalmology screening was 0.25 (95% CI, 0.07-0.85; P= .03). Duration of time in practice of over 15 years and disagreement with practice guidelines were associated with better outcomes. There was no association between physician sex, internal medicine training, or number of patients with diabetes in the practice and the implementation of outcomes. There was a highly significant association between the implementation of an outcome and the implementation of the other 2, resulting in a nonhomogeneous distribution of health care delivery. Physicians' estimate of their rate of implementation of outcomes, as assessed by the questionnaires, overestimated their actual performance while being in proportion with the documented rates. Most physicians took responsibility for the nonimplementation, accepting that it was an oversight on their part as opposed to an encounter with patient resistance. CONCLUSIONS: Most physicians believe that the lack of implementation of the measures for preventive care in patients with diabetes mellitus is an oversight. The oversight is more prevalent in the practices of busy physicians. The result is a nonhomogeneous distribution of health care. Computer reminders might be the solution.

Selective contracting and patient outcomes: a case study of formulary restrictions for selective serotonin reuptake inhibitor antidepressants.

OBJECTIVES: Many health maintenance organizations (HMOs) have selected 1 or 2 selective serotonin reuptake inhibitors (SSRIs) as their preferred drug for treating depression. This study investigated the effect of "single-drug" formulary restrictions on the likelihood of drug therapy completion for new patients, controlling for initial SSRIs used and other factors. METHODS: Prescription drug and medical record data for 187 patients who were newly prescribed SSRIs were retrieved from a single California group practice consisting of 22 board-certified primary care physicians. The group practice contracted with 2 independent practice association-model HMOs with different SSRI formulary restrictions. A multivariate analysis of drug therapy completion was conducted and 2 sensitivity analyses were performed. Completed therapy was based on the patient having achieved 6 months of uninterrupted therapy at a minimum therapeutic dose. RESULTS: Patients from the HMO with a single preferred SSRI (paroxetine) were 80% less likely to complete therapy than were patients from the HMO with 2 preferred SSRIs (fluoxetine and paroxetine) (odds ratio [OR] = 0.200, 95% confidence interval [CI] = 0.083-0.430). This formulary effect was independent of the initial drug used to treat the patient. Drug selection was also found to affect completion rates. Patients treated with sertraline were significantly less likely to complete therapy than were patients treated with fluoxetine (OR = 0.319, 95% CI = 0.105-0.968). Similar results were found for patients taking paroxetine relative to fluoxetine (OR = 0.357, 95% CI = 0.149-0.853). CONCLUSION: These results suggest that the use of single-product formularies may have unintended consequences on patient completion rates, independent of whether or not the most effective product is selected for preferred formulary status.

Changes in high density lipoprotein cholesterol after initiation of insulin therapy in non-insulin dependent diabetes mellitus: relationship to changes in body weight.

To determine the interrelationships of serum lipoproteins and body weight changes with insulin therapy, 55 diabetics (mean age 52.0 +/- 2.2 years), had measurements of body weight, sum of skinfold thickness, fasting serum glucose, serum high density (HDL-C) and low density (LDL-C) lipoprotein cholesterol and serum triglycerides before and 6 weeks after beginning insulin. At entry HDL-C had a significant (p less than 0.05) negative correlation with indices of body weight-body mass index, relative weight and a significant positive correlation with serum triglycerides but no significant association with sum of skinfold thickness, fasting serum glucose or LDL-C. The relationships were seen mainly in patients who previously had not been receiving oral hypoglycemic medications. Insulin significantly increased HDL-C and body weight, and decreased glucose, triglycerides and LDL-C. Changes in HDL-C showed a significant inverse association with changes in triglycerides and direct correlation with changes in body weight, but no significant association with changes in fasting serum glucose or LDL-C. Thus, insulin therapy of diabetes mellitus favorably affects HDL-C concentration perhaps by altering triglyceride metabolism and represents a unique situation where increases in body weight are associated with increases in serum HDL-C concentration.

A randomized clinical trial comparing behavior modification and individual counseling in the nutritional therapy of non-insulin-dependent diabetes mellitus: comparison of the effect on blood sugar, body weight, and serum lipids.

To determine whether a group behavior modification approach might be preferable to individual counseling in the nutritional therapy of non-insulin-dependent diabetes mellitus, 40 adults younger than 65 yr of age with diabetes mellitus who were not receiving insulin were randomized to either a program of individualized dietary review and recommendations or a program of group meetings aimed at controlling the signals leading to overeating and noncompliance with a diabetic dietary regimen. Statistically significant (P less than 0.05) decreases in body weight, sum skin-fold thickness, fasting serum glucose, and serum triglycerides but not LDL-C or HDL-C were observed. The individual counseling group had a greater amount of weight loss than the behavior modification group. There were no significant (P greater than 0.05) differences between the two groups with respect to the biochemical outcome variables. Patient characteristics assessed at entry--namely anxiety, internal versus external locus of control and perceived disease severity, and compliance with advice--were significantly associated with weight loss in the behavior modification group while only the latter index was of value in the individual counseling group. Thus, our use of these programs does not identify a clear advantage of either approach in the nutritional therapy of non-insulin-dependent diabetic patients.

Relationship of weight loss and cigarette smoking to changes in high-density lipoprotein cholesterol.

To determine the effect of weight loss on serum high-density lipoprotein cholesterol (HDL-C), we measured serum HDL-C as well as total cholesterol and triglycerides in 65 subjects 56 women and 9 men, mean age 41.1 +/- 1.5 (+/- SEM yr) before and after a weight reduction program. At entry into the program there was a significant correlation between HDL-C and several indices of overweight--relative weight, body mass index and sum of skinfold thickness. For all subjects, despite a significant weight loss of 4.5 kg or 5.8% of initial body weight and significant decrease in sum of skinfold thickness, there was no significant increase in HDL-C or correlation between changes in HDL-C and change in body weight or skinfold thickness. For women, but not men, a weak negative correlation between change in HDL-C and change in weight or percentage change in weight was observed. However, in the subset of women who were current cigarette smokers a significant (p less than 0.01) correlation was observed between change in HDL-C and change in weight (r = -0.876) and percentage change in weight (r = -0.881). Thus a modest weight loss is not usually associated with a significant increase in serum HDL-C concentration except in cigarette smoking women.

Changes in plasma high-density lipoprotein cholesterol concentration after weight reduction in grossly obese subjects.

Changes in serum lipoproteins associated with weight loss were assessed in 13 grossly obese (relative weight 183%) patients who had participated in an outpatient semi-starvation diet consisting of liquid protein and carbohydrate. At the follow-up examination an average of six and a half months after the start of refeeding the mean weight loss was 16.1 +/- 4.5 kg or 15% of initial body weight. Significant increases in high-density lipoprotein (HDL) cholesterol of 0.16 +/- 0.05 mmol/l (6 +/- 2 mg/100 ml) and decreases in triglycerides (0.8 +/- 0.23 mmol/l; 73 +/- 20 mg/100 ml) and fasting blood sugar (0.6 +/- 0.22 mmol/l; 11 +/- 4 mg/100 ml) were observed. Changes in HDL cholesterol correlated significantly with changes in weight (r = 0.667) and percentage change in weight. The intercept of the regression equation relating HDL cholesterol to percentage change in weight was -7.3, indicating that a change in HDL cholesterol greater than zero required a weight loss of at least 7.3% of body weight. Thus, weight loss can significantly increase HDL cholesterol concentrations but a considerable amount of weight must be lost to produce a significant increase in HDL cholesterol concentration.

Triglyceride removal from very low density lipoproteins in vivo as a function of their triglyceride content.

Rabbit very low density lipoproteins (VLDL) were fractionated in 3 subfractions differing in density and triglyceride (TG) content. The fraction of total weight represented by triglycerides was: VLDL1 TG = 71%, VLDL2 TG = 62%, VLDL3 TG = 55%. No other difference in composition was observed. After intravenous administration of radioglycerol all subfractions were labelled and the distribution of radioactivity in their glycerolipids was the same. In 5 rabbits, a biologically labelled triglyceride-rich VLDL1 subfraction preparation was administered and the specific activity of triglyceride was determined in all 3 subfractions in serial samples. A precursor--product relationship between VLDL1 TG and VLDL TG in other subfractions was not observed. In another set of experiments the disappearance rates of VLDL TG from subfractions were determined in recipient rabbits. The half-lives were: VLDL1 TG = 9.5 +/- 1.3 min, VLDL2 TG : 16.0 +/- 1.3 min, VLDL3 TG: 26.9 +/- 1.3 min. It is concluded that triglyceride removal from a VLDL subfraction varies inversely with its triglyceride content. A role for partial VLDL lipolysis in this metabolic heterogeneity was not established.

Turnover and recycling of glucose in man during prolonged fasting.

The effect of prolonged (3-5 wk) fasting on tracer-determined glucose turnover and of recycling radioactive glucose has been examined. We followed the specific activity of plasma glucose after the simultaneous administration of 1-14C-glucose and 3-3H-glucose. The rate of glucose turnover decreased during prolonged fasting. Recycling of radioactive glucose was estimated by two different techniques: (1) the appearance of 14C in positions 2 to 6 glucose was measured; (2) the difference in the slopes of specific activity decline for 1-14C-glucose and for 3-3H-glucose was calculated. The two methods of estimating the radioactive recycling gave results similar to each other. The amount of glucose recycled did not change during prolonged fasting. However, in view of the decline in glucose production during fasting, the proportion of glucose production which was represented by recycling increased. Based on weight and urinary nitrogen loss an estimate of the glucose production from amino acids and glycerol was obtained. The difference between the rate of glucose production from the contribution of amino acids and glycerol and that estimated by radioisotopic techniques was much larger than the measured rate of recycling. This finding suggests that either a large exchange of 12C with 14C occurred in some glycolytic intermediates or that a hitherto unknown source of carbon for glucose production appeared during prolonged fasting.

The effects of prolonged fasting on plasma triglyceride kinetics in man.

Studies were undertaken to examine triglyceride turnover in obese humans on isocaloric balanced diets and during prolonged (3-5 wk) fasting. The data were related to plasma concentrations of insulin (IRI), glucagon (IRG), and free fatty acids (FFA) and to blood ketone concentrations. The triglyceride turnover rates were also related to the plasma triglyceride concentration. This relationship was the same in the obese on isocaloric balanced diets as that we have previously observed in lean humans on similar diets. The relationship between triglyceride turnover and concentration changed during prolonged fasting in a way that suggested that triglyceride removal was impaired. This viewpoint is consistent with the known effects of fasting on adipose tissue lipoprotein lipase activity. In another group of fasted obese, refed with a hypocaloric diet, the relationship returned toward normal. In addition to the impaired triglyceride removal, prolonged fasting resulted in a decrease in triglyceride production. This decrease occurred despite an increase in plasma FFA. After 3-5 wk of fasting the IRI was about 50% of the initial value, while the IRG was the same as the initial value. While triglyceride production fell during fasting, the blood ketone concentration rose. Others have seen similar changes in ketones and triglycerides in livers perfused with medium in which the ratio of insulin to glucagon fell. The rate of triglyceride production was not related to body weight. However, regardless of nutritional state, it was positively related to the basal plasma insulin levels. These data indicate that, in man as in animal preparations, insulin may regulate hepatic triglyceride production.