title: Sex Differences in the Rate, Timing, and Principal Diagnoses of 30-Day Readmissions in Younger Patients with Acute Myocardial Infarction.
abstract: BACKGROUND
  Young women (<65 years) experience a 2- to 3-fold greater mortality risk than younger men after an acute myocardial infarction. However, it is unknown whether they are at higher risk for 30-day readmission, and if this association varies by age. We examined sex differences in the rate, timing, and principal diagnoses of 30-day readmissions, including the independent effect of sex following adjustment for confounders.
  
  
  RESULTS
  We included patients aged 18 to 64 years with a principal diagnosis of acute myocardial infarction. Data were used from the Healthcare Cost and Utilization Project-State Inpatient Database for California (07-09). Readmission diagnoses were categorized by using an aggregated version of the Centers for Medicare and Medicaid Services' Condition Categories, and readmission timing was determined from the day after discharge. Of 42,518 younger patients with acute myocardial infarction (26.4% female), 4775 (11.2%) had at least 1 readmission. The 30-day all-cause readmission rate was higher for women (15.5% versus 9.7%, P<0.0001). For both sexes, readmission risk was highest on days 2 to 4 after discharge and declined thereafter, and women were more likely to present with noncardiac diagnoses (44.4% versus 40.6%, P=0.01). Female sex was associated with a higher rate of 30-day readmission, which persisted after adjustment (hazard ratio, 1.22; 95% confidence interval, 1.15-1.30). There was no significant interaction between age and sex on readmission.
  
  
  CONCLUSIONS
  In comparison with men, younger women have a higher risk for readmission, even after the adjustment for confounders. The timing of 30-day readmission was similar in women and men, and both sexes were susceptible to a wide range of causes for readmission.
authors.affiliation: From the Center for Outcomes Research and Evaluation (CORE), Yale-New Haven Hospital, New Haven, CT (R.P.D., I.R., Y.W., K.D., K.M., S.V.N., A.F.H., H.M.K.); Section of Cardiovascular Medicine (R.P.D., I.R., Y.W., K.D., S.V.N., H.M.K.) and the Robert Wood Johnson Foundation Clinical Scholars Program (H.M.K.), New Haven, CT; Discipline of Medicine, The Queen Elizabeth Hospital, University of Adelaide, Adelaide SA (I.R.); Saint Luke's Mid America Heart Institute/University of Missouri-Kansas City, Kansas City, MO (J.A.S.); and Department of Health Policy and Management, Yale School of Public Health, New Haven, CT (H.M.K.). Dr Ranasinghe was affiliated with the Center for Outcomes Research and Evaluation, Yale-New Haven Hospital, Section of Cardiovascular Medicine, New Haven, CT during the time the work was conducted. rachel.dreyer@yale.edu.
authors.forename: Rachel P
authors.initials: RP
authors.lastname: Dreyer
authors.affiliation: From the Center for Outcomes Research and Evaluation (CORE), Yale-New Haven Hospital, New Haven, CT (R.P.D., I.R., Y.W., K.D., K.M., S.V.N., A.F.H., H.M.K.); Section of Cardiovascular Medicine (R.P.D., I.R., Y.W., K.D., S.V.N., H.M.K.) and the Robert Wood Johnson Foundation Clinical Scholars Program (H.M.K.), New Haven, CT; Discipline of Medicine, The Queen Elizabeth Hospital, University of Adelaide, Adelaide SA (I.R.); Saint Luke's Mid America Heart Institute/University of Missouri-Kansas City, Kansas City, MO (J.A.S.); and Department of Health Policy and Management, Yale School of Public Health, New Haven, CT (H.M.K.). Dr Ranasinghe was affiliated with the Center for Outcomes Research and Evaluation, Yale-New Haven Hospital, Section of Cardiovascular Medicine, New Haven, CT during the time the work was conducted.
authors.forename: Isuru
authors.initials: I
authors.lastname: Ranasinghe
authors.affiliation: From the Center for Outcomes Research and Evaluation (CORE), Yale-New Haven Hospital, New Haven, CT (R.P.D., I.R., Y.W., K.D., K.M., S.V.N., A.F.H., H.M.K.); Section of Cardiovascular Medicine (R.P.D., I.R., Y.W., K.D., S.V.N., H.M.K.) and the Robert Wood Johnson Foundation Clinical Scholars Program (H.M.K.), New Haven, CT; Discipline of Medicine, The Queen Elizabeth Hospital, University of Adelaide, Adelaide SA (I.R.); Saint Luke's Mid America Heart Institute/University of Missouri-Kansas City, Kansas City, MO (J.A.S.); and Department of Health Policy and Management, Yale School of Public Health, New Haven, CT (H.M.K.). Dr Ranasinghe was affiliated with the Center for Outcomes Research and Evaluation, Yale-New Haven Hospital, Section of Cardiovascular Medicine, New Haven, CT during the time the work was conducted.
authors.forename: Yongfei
authors.initials: Y
authors.lastname: Wang
authors.affiliation: From the Center for Outcomes Research and Evaluation (CORE), Yale-New Haven Hospital, New Haven, CT (R.P.D., I.R., Y.W., K.D., K.M., S.V.N., A.F.H., H.M.K.); Section of Cardiovascular Medicine (R.P.D., I.R., Y.W., K.D., S.V.N., H.M.K.) and the Robert Wood Johnson Foundation Clinical Scholars Program (H.M.K.), New Haven, CT; Discipline of Medicine, The Queen Elizabeth Hospital, University of Adelaide, Adelaide SA (I.R.); Saint Luke's Mid America Heart Institute/University of Missouri-Kansas City, Kansas City, MO (J.A.S.); and Department of Health Policy and Management, Yale School of Public Health, New Haven, CT (H.M.K.). Dr Ranasinghe was affiliated with the Center for Outcomes Research and Evaluation, Yale-New Haven Hospital, Section of Cardiovascular Medicine, New Haven, CT during the time the work was conducted.
authors.forename: Kumar
authors.initials: K
authors.lastname: Dharmarajan
authors.affiliation: From the Center for Outcomes Research and Evaluation (CORE), Yale-New Haven Hospital, New Haven, CT (R.P.D., I.R., Y.W., K.D., K.M., S.V.N., A.F.H., H.M.K.); Section of Cardiovascular Medicine (R.P.D., I.R., Y.W., K.D., S.V.N., H.M.K.) and the Robert Wood Johnson Foundation Clinical Scholars Program (H.M.K.), New Haven, CT; Discipline of Medicine, The Queen Elizabeth Hospital, University of Adelaide, Adelaide SA (I.R.); Saint Luke's Mid America Heart Institute/University of Missouri-Kansas City, Kansas City, MO (J.A.S.); and Department of Health Policy and Management, Yale School of Public Health, New Haven, CT (H.M.K.). Dr Ranasinghe was affiliated with the Center for Outcomes Research and Evaluation, Yale-New Haven Hospital, Section of Cardiovascular Medicine, New Haven, CT during the time the work was conducted.
authors.forename: Karthik
authors.initials: K
authors.lastname: Murugiah
authors.affiliation: From the Center for Outcomes Research and Evaluation (CORE), Yale-New Haven Hospital, New Haven, CT (R.P.D., I.R., Y.W., K.D., K.M., S.V.N., A.F.H., H.M.K.); Section of Cardiovascular Medicine (R.P.D., I.R., Y.W., K.D., S.V.N., H.M.K.) and the Robert Wood Johnson Foundation Clinical Scholars Program (H.M.K.), New Haven, CT; Discipline of Medicine, The Queen Elizabeth Hospital, University of Adelaide, Adelaide SA (I.R.); Saint Luke's Mid America Heart Institute/University of Missouri-Kansas City, Kansas City, MO (J.A.S.); and Department of Health Policy and Management, Yale School of Public Health, New Haven, CT (H.M.K.). Dr Ranasinghe was affiliated with the Center for Outcomes Research and Evaluation, Yale-New Haven Hospital, Section of Cardiovascular Medicine, New Haven, CT during the time the work was conducted.
authors.forename: Sudhakar V
authors.initials: SV
authors.lastname: Nuti
authors.affiliation: From the Center for Outcomes Research and Evaluation (CORE), Yale-New Haven Hospital, New Haven, CT (R.P.D., I.R., Y.W., K.D., K.M., S.V.N., A.F.H., H.M.K.); Section of Cardiovascular Medicine (R.P.D., I.R., Y.W., K.D., S.V.N., H.M.K.) and the Robert Wood Johnson Foundation Clinical Scholars Program (H.M.K.), New Haven, CT; Discipline of Medicine, The Queen Elizabeth Hospital, University of Adelaide, Adelaide SA (I.R.); Saint Luke's Mid America Heart Institute/University of Missouri-Kansas City, Kansas City, MO (J.A.S.); and Department of Health Policy and Management, Yale School of Public Health, New Haven, CT (H.M.K.). Dr Ranasinghe was affiliated with the Center for Outcomes Research and Evaluation, Yale-New Haven Hospital, Section of Cardiovascular Medicine, New Haven, CT during the time the work was conducted.
authors.forename: Angela F
authors.initials: AF
authors.lastname: Hsieh
authors.affiliation: From the Center for Outcomes Research and Evaluation (CORE), Yale-New Haven Hospital, New Haven, CT (R.P.D., I.R., Y.W., K.D., K.M., S.V.N., A.F.H., H.M.K.); Section of Cardiovascular Medicine (R.P.D., I.R., Y.W., K.D., S.V.N., H.M.K.) and the Robert Wood Johnson Foundation Clinical Scholars Program (H.M.K.), New Haven, CT; Discipline of Medicine, The Queen Elizabeth Hospital, University of Adelaide, Adelaide SA (I.R.); Saint Luke's Mid America Heart Institute/University of Missouri-Kansas City, Kansas City, MO (J.A.S.); and Department of Health Policy and Management, Yale School of Public Health, New Haven, CT (H.M.K.). Dr Ranasinghe was affiliated with the Center for Outcomes Research and Evaluation, Yale-New Haven Hospital, Section of Cardiovascular Medicine, New Haven, CT during the time the work was conducted.
authors.forename: John A
authors.initials: JA
authors.lastname: Spertus
authors.affiliation: From the Center for Outcomes Research and Evaluation (CORE), Yale-New Haven Hospital, New Haven, CT (R.P.D., I.R., Y.W., K.D., K.M., S.V.N., A.F.H., H.M.K.); Section of Cardiovascular Medicine (R.P.D., I.R., Y.W., K.D., S.V.N., H.M.K.) and the Robert Wood Johnson Foundation Clinical Scholars Program (H.M.K.), New Haven, CT; Discipline of Medicine, The Queen Elizabeth Hospital, University of Adelaide, Adelaide SA (I.R.); Saint Luke's Mid America Heart Institute/University of Missouri-Kansas City, Kansas City, MO (J.A.S.); and Department of Health Policy and Management, Yale School of Public Health, New Haven, CT (H.M.K.). Dr Ranasinghe was affiliated with the Center for Outcomes Research and Evaluation, Yale-New Haven Hospital, Section of Cardiovascular Medicine, New Haven, CT during the time the work was conducted.
authors.forename: Harlan M
authors.initials: HM
authors.lastname: Krumholz
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000175:diagnosis* / Q000453:epidemiology* / Q000628:therapy; D010359:Patient Readmission / Q000639:trends*; D012189:Retrospective Studies; D012307:Risk Factors; D012727:Sex Characteristics; D013997:Time Factors; D055815:Young Adult
keywords: anterior wall myocardial infarction; patient readmission; posthospital syndrome; sex differences; women