Table 2.
Selected Matched Patient and Hospital Characteristics
| Characteristics (percent unless noted) | Before match | Matched | Matched | Before match | Before match | After match |
|---|---|---|---|---|---|---|
| Patients in better nursing resourced hospitals | Patients in better nursing resourced hospitals | Patients in worse nursing resourced hospitals | Patients in worse nursing resourced hospitals | Standardized difference | Standardized difference | |
| (n = 86,609) | (n = 74,045) | (n = 74,045) | (n = 276,857) | |||
| Patient characteristics | ||||||
| Age, mean (years) | 80.3 | 80.6 | 80.7 | 80.7 | − 0.05 | − 0.01 |
| Male | 47.6 | 47.1 | 46.9 | 47.7 | 0.00 | 0.00 |
| Black | 8.2 | 6.9 | 7.3 | 5.3 | 0.11 | − 0.01 |
| Hispanic | 13.3 | 14.3 | 13.4 | 6.3 | 0.24 | 0.03 |
| Probability of 30-day mortality | 17.5 | 17.3 | 17.2 | 16.0 | 0.11 | 0.01 |
| Emergency admission | 76.9 | 74.9 | 75.8 | 85.4 | − 0.22 | − 0.02 |
| Transfer-in | 0.6 | 0.6 | 0.7 | 0.7 | − 0.02 | − 0.01 |
| Comorbidities | ||||||
| Hypertension | 84.7 | 85.1 | 87.2 | 87.5 | − 0.08 | − 0.06 |
| Diabetes | 44.3 | 44.2 | 46.4 | 45.0 | − 0.01 | − 0.04 |
| Renal failure | 43.7 | 43.6 | 43.6 | 41.5 | 0.04 | 0.00 |
| Congestive heart failure | 38.8 | 38.6 | 37.7 | 38.5 | 0.00 | 0.02 |
| Chronic obstructive pulmonary disease | 32.9 | 33.3 | 35.0 | 38.7 | − 0.12 | − 0.04 |
| Stroke | 12.3 | 12.2 | 11.4 | 11.5 | 0.02 | 0.02 |
| Past AMI | 3.8 | 3.8 | 3.7 | 4.0 | − 0.01 | 0.00 |
| Medical conditions | ||||||
| Acute myocardial infarction | 11.4 | 12.0 | 12.0 | 14.2 | − 0.08 | 0.00 |
| Congestive heart failure | 22.1 | 22.1 | 22.1 | 24.0 | − 0.05 | 0.00 |
| Pneumonia | 16.8 | 17.3 | 17.3 | 20.5 | − 0.09 | 0.00 |
| Stroke | 35.6 | 34.4 | 34.4 | 27.9 | 0.16 | 0.00 |
| Sepsis | 14.1 | 14.3 | 14.3 | 13.4 | 0.02 | 0.00 |
| Hospital characteristics | ||||||
| Small (< 250 beds) | 25.7 | 30.0 | 30.0 | 47.6 | − 0.47 | 0.00 |
| Large (≥ 250 beds) | 74.3 | 70.0 | 70.0 | 52.4 | 0.47 | 0.00 |
| Beds, mean | 422.5 | 383.0 | 375.3 | 295.0 | 0.63 | 0.04 |
| Non-teaching | 50.1 | 58.6 | 58.6 | 65.0 | − 0.30 | 0.00 |
| Minor teaching | 21.2 | 24.8 | 24.8 | 28.3 | − 0.17 | 0.00 |
| Major teaching | 28.7 | 16.7 | 16.7 | 6.7 | 0.60 | 0.00 |
| Resident to bed ratio, mean | 0.23 | 0.13 | 0.12 | 0.07 | 0.61 | 0.05 |
| High technology status | 84.2 | 81.5 | 81.5 | 49.0 | 0.80 | 0.00 |
| Nursing resources | ||||||
| Patient-to-nurse staffing ratio, mean | 4.37 | 4.40 | 5.52 | 5.77 | − 1.93 | − 1.55 |
| Nurse skill mix, mean | 0.84 | 0.85 | 0.77 | 0.78 | 1.55 | 1.69 |
| Proportion of nurses with a BSN or higher | 68.70 | 67.21 | 47.35 | 44.77 | 2.00 | 1.66 |
| Nurse work environment, mean | 3.04 | 3.03 | 2.73 | 2.70 | 1.67 | 1.49 |
After matching, the number of patients in the better resourced hospitals declines from 86,609 to 74,045 because not all patients in the best resourced hospitals could be matched with patients in a worse resourced hospital. The standardized differences after matching among the four measures of nursing resources are large (as expected) since the matching algorithm selected patient pairs who were in distinctly different hospitals with respect to their nursing resources