Table 2

Sample characteristics and unadjusted rates of patient safety events per hospitalisation

VariableOverall samplePatient safety eventP value*†Voluntary patient safety eventP value*‡Automated patient safety eventP value*§
n=141 877n=19 280n=15 048n=6459
13.6%10.6%4.6%
Sex
 Female58.3%50.6%<0.000151.0%<0.000147.7%<0.0001
Age (years)<0.0001<0.0001<0.0001
 18–299.4%4.6%5.1%2.5%
 31–4015.8%7.4%8.2%4.6%
 41–509.2%8.0%8.0%8.1%
 51–6423.6%24.6%23.9%27.3%
 ≥6542.1%55.4%54.8%57.5%
Race/Ethnicity<0.0001<0.0001<0.0001
 White64.3%67.5%67.7%66.3%
 Black12.7%13.1%12.7%14.1%
 Latino4.4%3.8%3.7%4.2%
 Asian5.2%3.4%3.5%3.2%
 Other13.3%12.3%12.4%12.3%
LEP10.1%10.1%0.9710.1%0.8710.6%0.14
Language<0.0001<0.0001<0.0001
 English89.9%89.9%89.9%89.4%<0.0001
 Spanish2.8%3.1%2.9%3.6%
 Chinese2.2%1.4%1.5%1.2%
 Russian1.1%1.4%1.5%1.4%
 Cape Verdean0.8%0.8%0.8%1.0%
 Other3.1%3.4%3.4%3.5%
Marital status<0.0001<0.0001<0.0001
 Married/Life partner49.0%43.4%42.9%43.9%
 Other51.0%56.6%57.1%56.1%
Insurance<0.0001<0.0001<0.0001
 Other§83.6%88.2%90.8%96.2%
 Medicaid¶16.4%11.8%9.3%3.8%
Length of stay3 (2 to 6)8 (4 to 15)<0.00017 (4 to 15)<0.000111 (6 to 21)
Service<0.0001<0.0001<0.0001
 Medicine45.7%58.4%56.4%64.4%
 Surgical31.6%31.5%32.0%31.1%
 Obstetrics and gynaecology18.4%6.0%7.1%1.7%
 Neurology4.3%4.1%4.5%2.8%
Primary diagnosis<0.0001<0.0001<0.0001
 Pregnancy related16.8%5.1%6.2%0.9%
 Circulatory system18.6%23.5%20.6%32.3%
 Digestive system11.0%10.9%10.1%12.2%
 Musculoskeletal/Connective tissue6.2%4.6%5.2%2.3%
 Pulmonary4.9%5.3%5.5%4.6%
 Injury and poisoning11.8%15.2%15.5%14.8%
 Haematology-oncology11.2%11.9%12.2%11.1%
 Other19.5%23.7%24.7%21.9%
Clinical risk score**0.86 (0.68 to 2.1)2.0 (0.85 to 5.9)<0.00012.0 (0.84 to 5.9)<0.00013.1 (1.1 to 8.9)
Year<0.0001<0.0001<0.0001
 20145.6%5.2%5.1%5.5%
 201523.2%21.9%22.1%21.1%
 201623.6%23.5%24.0%22.3%
 201723.9%24.4%23.9%25.9%
 201823.7%24.9%24.9%25.3%
  • *P values significant at α<0.05.

  • †Compared with those without a patient safety event, column percent.

  • ‡Compared with those without a voluntary reported patient safety event, column per cent.

  • §Combined: commercial, Medicare, other.

  • ¶Medicaid or uninsured.

  • **Risk of death.

  • ††Compared with those without an automatically reported patient safety event, column per cent.

  • ‡‡Based on clinical classification software.

  • LEP, limited English proficiency.;