Table 6.

Multivariable Analysis for Shock-Related Healthcare Expenditures

VariablesInpatient HCUOutpatient HCU
Ratio*P Value95% CI for RatioRatio*P Value95% CI for Ratio
No. of days post-implant1.0000.6561.000–1.0001.0000.8481.000–1.001
Proportion of previous shocks with HCU1.1700.3130.863–1.5851.3070.1740.888–1.922
Shock event number1.0330.3320.968–1.1020.9480.1270.885–1.015
No. of shocks in current event1.0180.0011.008–1.0281.0370.0321.003–1.072
Age1.0060.4780.989–1.0240.9730.0120.952–0.994
Age (squared)1.0000.8811.000–1.0001.0000.3860.999–1.000
Sex, female0.8180.0840.652–1.0270.7200.0820.498–1.042
Primary insurance, Medicare0.9750.8950.664–1.4301.0630.8140.637–1.775
Health plan (ref: HMO)
 Comprehensive/FFS0.6360.0290.423–0.9552.2460.0011.391–3.628
 EPO/PPO0.8980.4320.686–1.1751.1190.5500.773–1.621
 POS1.3180.2560.818–2.1251.3550.3510.716–2.564
Comorbid conditions
 Acute MI or IHD0.9300.5270.741–1.1661.3850.0311.030–1.864
 Conduction disorder0.8100.2110.583–1.1271.3680.1510.892–2.098
 Chronic kidney disease0.8980.5140.649–1.2410.9080.8070.417–1.975
 Arrhythmia (atrial)0.9230.5010.730–1.1660.6800.0170.495–0.935
 Arrhythmia (ventricular)1.0180.8890.789–1.3151.1330.4390.826–1.554
 Cardiac arrest1.2560.1530.919–1.7170.9300.8000.529–1.634
 Arrhythmia (dysrhythmia)0.8600.3620.621–1.1901.1660.3920.821–1.655
Preimplant medication use
 Antidiabetic medications0.7840.0490.615–0.9990.9000.5620.631–1.284
 β-blockers1.0530.6320.852–1.3021.0080.9540.755–1.347
 Oral anticoagulants1.0230.8550.798–1.3120.7770.1570.547–1.102
Device type (ref: VR)
 CRT-D1.0400.8180.745–1.4521.2810.2020.876–1.873
 DR0.8490.2840.630–1.1450.8540.3900.596–1.223
Total cardiac related preshock expenditures1.0000.0781.000–1.0001.0000.4411.000–1.000
Total noncardiac related preshock expenditures1.0000.0131.000–1.0001.0000.4981.000–1.000
Shock type (ref: appropriate)
 Inappropriate0.9440.5930.765–1.1651.0420.7900.770–1.410
 Indeterminate1.5100.0780.955–2.3871.3100.3280.763–2.247
  • CI indicates confidence interval; CRT-D, cardiac resynchronization therapy defibrillator; DR, dual-chamber implantable cardioverter–defibrillator; EPO, exclusive provider organization; FFS, fee-for-service; HCU, healthcare utilization; IHD, ischemic heart disease; MI, myocardial infarction; POS, point of service; PPO, preferred provider organization; and VR, single-chamber implantable cardioverter–defibrillator.

  • * Values <1 indicate that variable is associated with lower costs; values >1 indicate that variable is associated with higher costs.

  • Significant predictor of expenditures.