Adverse hospital events for mentally ill patients undergoing coronary artery bypass surgery.

An estimated 5.4 percent of American adults have severe mental illness including psychiatric and substance-abuse disorders (Kessler et al. 2002). Mental disorders are associated with an increased risk of coronary heart disease (CHD) (Kawachi et al. 1994; Lett et al. 2004; Shah et al. 2004; Hennekens et al. 2005), and strongly predict worse cardiac outcomes after medical or surgical interventions of CHD (Connerney et al. 2001; Druss et al. 2001; Blumenthal et al. 2003; Pignay-Demaria et al. 2003; Lett et al. 2004; Shemesh et al. 2004). For example, patients with coexisting major depression show more frequent readmissions after coronary artery bypass graft (CABG) surgery (Connerney et al. 2001; Pignay-Demaria et al. 2003; Lett et al. 2004), and higher mortality (Blumenthal et al. 2003) up to 12 years postoperatively. Despite the heightened burden of CHD among mentally ill patients, less is known about the quality of cardiac service that they receive and how their mental illness can complicate the quality, safety, and outcomes of cardiac interventions during nonpsychiatric hospitalizations. Druss et al. reported that after hospitalizations for myocardial infarction, patients with mental disorders were less likely to receive indicated medical prescriptions (Druss et al. 2001) or revascularization procedures (Druss et al. 2000), suggesting suboptimal quality of care in these medically vulnerable patients. Moreover, one recent study found that mentally ill patients undergoing CABG surgery in New York State tended to be treated by lower-quality cardiac surgeons (Li et al. 2007). The issue of quality and safety of hospital care was highlighted by the Institute of Medicine (IOM)'s report To Err Is Human: Building a Safer Health System (Institute of Medicine Committee on the Quality of Health Care 2000), which estimated that up to 98,000 hospital deaths each year were due to preventable medical errors. Preventable hospital adverse events, such as major complications after the CABG procedure, may be caused by mistake or delay in diagnosis and treatment, inadequate monitoring or follow-up of treatment, and failure in communication (Leape et al. 1993). It is conceivable that compared with CABG patients without mental illness, those who are mentally ill may experience higher rate of postoperative complications because of their concomitant pathology associated with mental disorders (Pignay-Demaria et al. 2003); the adverse effects of antipsychotic medications (Buckley and Sanders 2000); their cognitive, affective, and behavioral abnormalities that cause miscommunications or noncompliance with treatment regimens (Kronish et al. 2006); and the likelihood of receiving care from lower-quality surgeons (Li et al. 2007). The objective of this study was to compare the occurrence of postoperative complications in patients with and without mental disorders who underwent isolated CABG surgery in New York State. We hypothesized that coexisting mental disorders were associated with higher rate of post-CABG complications and injuries during hospital stay. We measured these adverse outcomes using the patient safety indicators (PSIs) that were developed by the Agency for Healthcare Research and Quality (AHRQ) (Miller et al. 2001; Romano et al. 2003; Agency for Healthcare Research and Quality 2006a).