Publications

BACKGROUND

Given the rising costs of health care, policymakers are increasingly interested in identifying the inefficiencies in our health care system. The objective of this study was to determine whether the overuse and misuse of health care services in the ambulatory setting has decreased in the past decade.

METHODS

Cross-sectional analysis of the 1999 and 2009 National Ambulatory Medical Care Survey and the outpatient department component of the National Hospital Ambulatory Medical Care Survey, which are nationally representative annual surveys of visits to non-federally funded ambulatory care practices. We applied 22 quality indicators using a combination of current quality measures and guideline recommendations. The main outcome measures were the rates of underuse, overuse, and misuse and their 95% CIs.

RESULTS

We observed a statistically significant improvement in 6 of 9 underuse quality indicators. There was an improvement in the use of antithrombotic therapy for atrial fibrillation; the use of aspirin, β-blockers, and statins in coronary artery disease; the use of β-blockers in congestive heart failure; and the use of statins in diabetes mellitus. We observed an improvement in only 2 of 11 overuse quality indicators, 1 indicator became worse, and 8 did not change. There was a statistically significant decrease in the overuse of cervical cancer screening in visits for women older than 65 years and in the overuse of antibiotics in asthma exacerbations. However, there was an increase in the overuse of prostate cancer screening in men older than 74 years. Of the 2 misuse indicators, there was a decrease in the proportion of patients with a urinary tract infection who were prescribed an inappropriate antibiotic.

CONCLUSIONS

We found significant improvement in the delivery of underused care but more limited changes in the reduction of inappropriate care. With the high cost of health care, these results are concerning.

α1-Adrenergic receptors (α1-ARs) elicit a negative inotropic effect (NIE) in the mouse right ventricular (RV) myocardium but a positive inotropic effect (PIE) in the left ventricular (LV) myocardium. Effects on myofilament Ca(2+) sensitivity play a role, but effects on Ca(2+) handling could also contribute. We monitored the effects of α1-AR stimulation on contraction and Ca(2+) transients using single myocytes isolated from the RV or LV. Interestingly, for both the RV and LV, we found heterogeneous myocyte inotropic responses. α1-ARs mediated either a PIE or NIE, although RV myocytes had a greater proportion of cells manifesting a NIE (68%) compared with LV myocytes (36%). Stimulation of a single α1-AR subtype (α1A-ARs) with a subtype-selective agonist also elicited heterogeneous inotropic responses, suggesting that the heterogeneity arose from events downstream of the α1A-AR subtype. For RV and LV myocytes, an α1-AR-mediated PIE was associated with an increased Ca(2+) transient and a NIE was associated with a decreased Ca(2+) transient, suggesting a key role for Ca(2+) handling. For RV and LV myocytes, α1-AR-mediated decreases in the Ca(2+) transient were associated with increased Ca(2+) export from the cell and decreased Ca(2+) content of the sarcoplasmic reticulum. In contrast, for myocytes with α1-AR-induced increased Ca(2+) transients, sarcoplasmic reticulum Ca(2+) content was not increased, suggesting that other mechanisms contributed to the increased Ca(2+) transients. This study demonstrates the marked heterogeneity of LV and RV cellular inotropic responses to stimulation of α1-ARs and reveals a new aspect of biological heterogeneity among myocytes in the regulation of contraction.