ABC | Volume 113, Nº1, July 2019

Original Article Oliveira et al Readmission of patients with coronary syndrome Arq Bras Cardiol. 2019; 113(1):42-49 beta blockers, angiotensin-converting enzyme inhibitors (ACEI), and angiotensin receptor blockers (ARBs). The use of these medications at home was also evaluated at readmission (collected from the medical records). Physical activity The practice of physical activity was evaluated using the short version of the IPAQ. 12,13 This instrument classifies the patient into four categories, based on the intensity levels of physical activity: very active, active, insufficiently active and inactive. In our study, “very active” and “active” individuals according to the IPAQ were considered “active”, and those classified as “insufficiently active” and “inactive” in the IPAQ were considered “inactive”. The level of physical activity at hospital admission, and 30 days and 180 days after discharge was assessed by telephone. Clinical features We evaluated the type of ACS at first admission, and the presence of previous systemic arterial hypertension (SAH), diabetes mellitus (DM), dyslipidemias, coronary artery disease (CAD), congestive heart failure, angina, AMI, angioplasty, myocardial revascularization and chronic kidney disease. All variables were categorized into present or absent (yes or no). Statistical analysis Categorical variables were expressed as absolute and relative frequency, and distribution of quantitative variables was tested for normality using the Kolmogorov-Smirnov test. Variables that met the assumption of normality were presented as mean and standard deviation. Associations between categorical variables were assessed using the chi-square test or the Fisher’s exact test, as appropriate. A p < 0.05 was set as statistically significant; all variables with p < 0.20 after association test and those that were risk factors for cardiovascular diseases were subjected to multiple logistic regression analysis. Fourteen variables– sex, type of health care, race, age, hypertension, dyslipidemia, DM, congestive heart failure, use of statins on day 180, educational attainment, smoking, alcohol consumption, type of ACS – were selected as independent variables in the regressionmodel, and readmission as dependent variable. The odds ratio (OR) and 95% confidence interval was used in the model. The Hosmer-Lemeshow goodness of fit test was used to evaluate the fitness of the model. All analyses were performed using the R software, version 3.4.0 (The R Core Team, 2016). 14 Results A total of 536 patients were considered eligible for the study. Mean age was 63.15 ± 12.26 years, and most of the were men (64.0%). One hundred fifteen readmitted patients were identified (21.5%). Readmissions occurred 122.74 ± 112.14 days after discharge from the first hospitalization. Among readmitted patients, 7% had the prognosis of “death”, and 68.7% were readmitted more than once within a one-year period. Regarding the reasons of hospital readmissions, 42.6% were ACS, 20.9% other cardiovascular causes (pulmonary hypertension, peripheral obstructive disease, second-degree atrioventricular block, and mitral insufficiency) and 36.52% other noncardiovascular causes (malnutrition, respiratory insufficiency, kidney disease, DM and complications, unspecified disorder of vestibular function, diverticulitis, hernioplasty, trauma and hyponatremia). Table 1 presents the association of readmission with socioeconomic variables with the type of health care provided, nutritional status and life style. White patients, patients with higher educational attainment, those with higher family income and users of private health care services showed higher readmission rates. Regarding clinical conditions associated with readmission (Table 2), readmission rates were higher in patients with STEMI, dyslipidemias, chronic kidney disease, congestive heart failure, angina, AMI, and previous angioplasty. With respect to the use of medications after hospital discharge (Table 3), only absence of statin 180 days after the ACS event was associated with hospital readmission. Factors associated with readmission were subjected to multiple logistic regression analysis (Table 4). Type of health care and congestive heart failure showed statistical significance. Users of private health care services had higher odds of rehospitalization than those attending public health clinics. However, patients with previous congestive heart failure had 1.81 times greater odds of readmissions. Discussion The readmission rate of 21.46% found in the present study was similar to that (24.5%) reported in the study byDreyer et al., 15 who evaluated the rate of readmissions in 3,536 patients within one year after AMI in the USA. A study conducted in Canada with 3,411 patients of both sexes reported a higher readmission rate (61.7%) in one year after first hospitalization for ACS. 7 Rehospitalization rates in our study were also lower than those reported by Ricci et al.(47.9%), 8 evaluating 30-day readmission in a complex care hospital. Sangu et al. 16 believe that readmission rates can be influenced by the time period of evaluation following discharge. Readmission rates can also be affected by geographic factors in a population. 17 Readmission rate is also a predictor of the performance of hospital activities and the occurrence of complications after discharge, 18 which can reflect the accessibility to primary health care services. Self-referral to hospitals may be explained by a difficult access to primary care services, and the idea of a treatment focused on acute rather than chronic care, which raises self-referral to complex care hospitals. 19,20 Readmission rates, however, are not always associated with the access to health care centers and quality of care provided. The rates may be associated with complexity of disease and patients’ individual features, including socioeconomic status and disease severity. On the other hand, planned readmissions have been associated with the quality of hospital care. 21,22 44