Table 2.
Multivariable analysis of patient-, provider-, and institutional-level characteristics and benzodiazepine use.
| Category | Descriptor | OR | 95% CI | P value |
|---|---|---|---|---|
| Patient level | ||||
| Anthropomorphic and demographic data | Age (yr) | |||
| 18–50 | Reference | – | – | |
| 51–60 | 0.67 | (0.58, 0.78) | <0.0001 | |
| 61–70 | 0.37 | (0.32, 0.42) | <0.0001 | |
| 71–80 | 0.14 | (0.12, 0.16) | <0.0001 | |
| >80 | 0.04 | (0.04, 0.05) | <0.0001 | |
| Sex | ||||
| Male | Reference | – | – | |
| Female | 0.95 | (0.89, 1.02) | 0.18 | |
| Race/ethnicity | ||||
| Caucasian | Reference | – | – | |
| Black | 0.80 | (0.70, 0.91) | 0.001 | |
| Hispanic | 0.95 | (0.65, 1.39) | 0.80 | |
| Other or multiracial | 0.85 | (0.74, 1.00) | 0.04 | |
| BMI∗ | ||||
| Underweight | 0.91 | (0.68, 1.20) | 0.49 | |
| Normal | Reference | – | – | |
| Overweight | 1.13 | (1.04, 1.22) | 0.004 | |
| Class I Obesity | 1.23 | (1.11, 1.36) | <0.0001 | |
| Class II Obesity | 1.15 | (1.00, 1.32) | 0.05 | |
| Class III Obesity | 1.02 | (0.85, 1.23) | 0.81 | |
| Preoperative status and comorbidities† | ASA physical status | |||
| 1–3 | Reference | – | – | |
| 4 | 0.87 | (0.80, 0.94) | 0.0005 | |
| Alcohol abuse | 1.14 | (0.78, 1.65) | 0.50 | |
| Cardiac arrhythmia | 0.95 | (0.88, 1.02) | 0.14 | |
| Chronic pulmonary disease | 0.98 | (0.91, 1.06) | 0.65 | |
| Congestive heart failure | 0.81 | (0.75, 0.87) | <0.0001 | |
| Depression | 1.02 | (0.92, 1.12) | 0.74 | |
| Diabetes mellitus | 0.87 | (0.80, 0.94) | 0.0006 | |
| Drug abuse | 1.29 | (1.02, 1.65) | 0.04 | |
| Hypertension | 0.90 | (0.83, 0.98) | 0.02 | |
| Liver disease | 0.89 | (0.76, 1.03) | 0.11 | |
| Obesity | 1.03 | (0.93, 1.15) | 0.55 | |
| Other neurological disorders | 0.75 | (0.66, 0.84) | <0.0001 | |
| Psychoses | 0.81 | (0.54, 1.22) | 0.32 | |
| Pulmonary circulation disorders | 0.85 | (0.78, 0.93) | 0.0005 | |
| Renal failure | 0.83 | (0.77, 0.91) | <0.0001 | |
| Valvular disease | 1.09 | (0.98, 1.20) | 0.10 | |
| Intraoperative data | Baseline MAP‡ | |||
| Hypotensive | 1.00 | (0.88, 1.13) | 0.99 | |
| Normotensive | Reference | – | – | |
| Stage 1 hypertension | 0.91 | (0.83, 1.00) | 0.05 | |
| Stage 2 hypertension | 0.77 | (0.68, 0.86) | <0.0001 | |
| Anaesthesia duration (h) | 1.11 | (1.08, 1.13) | <0.0001 | |
| Cardiopulmonary bypass used | 2.26 | (1.99, 2.55) | <0.0001 | |
| Procedure type | ||||
| CABG only | Reference | – | – | |
| Valve and CABG only | 0.80 | (0.71, 0.91) | 0.0006 | |
| Valve only | 0.94 | (0.85, 1.05) | 0.29 | |
| Other cardiac¶ | 0.81 | (0.72, 0.91) | 0.0004 | |
| Year of surgery | ||||
| 2014 | reference | – | – | |
| 2015 | 0.88 | (0.76, 1.01) | 0.06 | |
| 2016 | 0.73 | (0.63, 0.83) | <0.0001 | |
| 2017 | 0.77 | (0.67, 0.89) | 0.0003 | |
| 2018 | 0.55 | (0.47, 0.63) | <0.0001 | |
| 2019 | 0.42 | (0.37, 0.49) | <0.0001 | |
| Provider level | ||||
| Mean case volume per year | ||||
| <2 | 0.44 | (0.25, 0.75) | 0.002 | |
| 2–9.5 | 1.43 | (0.97, 2.12) | 0.09 | |
| 9.5–19.5 | 0.86 | (0.62, 1.20) | 0.36 | |
| 19.5–37.5 | 0.73 | (0.55, 0.99) | 0.04 | |
| >37.5 | Reference | – | – | |
| Institution level | ||||
| Mean case volume per year | ||||
| <291.5 | 1.51 | (0.07, 33.7) | 0.70 | |
| 291.5–451.7 | 1.05 | (0.04, 25.2) | 0.98 | |
| 451.7–704.3 | 1.14 | (0.04, 29.7) | 0.95 | |
| 704.3–2488.5 | 6.5 | (0.17, 250.4) | 0.32 | |
| >2488.5 | Reference | – | – | |
| University affiliation | ||||
| Non-academic | Reference | – | – | |
| Academic | 0.08 | (0.02, 0.35) | 0.0007 | |
CABG, coronary artery bypass grafting; CI, confidence interval; OR, odds ratio.
BMI categorized using WHO categories29: Underweight (<18.5 kg m−2); Normal (18.5–24.9 kg m−2, reference); Overweight (25.0–29.9 kg m−2); Class I Obesity (30.0–34.9 kg m−2); Class II Obesity (35.0–39.9 kg m−2); Class III Obesity (>40.0 kg m−2).
Comorbidities as defined by the Elixhauser Comorbidity Enhanced International Classification of Diseases, Ninth and Tenth Revisions, Clinical Modification Algorithm.30
As defined by the Seventh Report of the Joint National Committee31 and National Heart, Lung, and Blood Institute’s Health Information for the Public32: hypotensive (<70 mm Hg), normotensive (70–107 mm Hg, reference), stage 1 hypertension (108–120 mm Hg), and stage 2 hypertension (>120 mm Hg).
Including Maze procedures, open atrial/ventricular septal defect repairs, cardiac mass excisions, pericardiectomies, isolated open epicardial lead placement, and coronary artery bypass or valve procedures involving pericardiectomy, atrial/ventricular septal defect repair.