TABLE 3

Median regression analysis showing changes in the median LOS following the introduction of rapid PCR

VariableNo. of patientsMedian LOS (h [95% CI])Change in LOS within the intervention groups (pre to post)aAdjusted DID analysisb
UnadjustedAdjustedb
Coefficient (95% CI)P valueCoefficient (95% CI)P valueCoefficient (95% CI)P value
Intervention group
    Regardless of test results
        Standard PCR953100.9 (96.2 to 109.9)Reference groupReference groupReference group
        Rapid PCR1,209101.8 (97.1 to 112.8)0.9 (−7.9 to 9.6)0.85−6.5 (−16.0 to 2.9)0.18−8.9 (−21.5 to 3.7)0.17
    Positive test results
        Standard PCR21098.6 (94.5 to 116.9)Reference groupReference groupReference group
        Rapid PCR44092.9 (81.5 to 98.6)−5.5 (−19.9 to 8.8)0.45−21.2 (−38.0 to −4.5)0.01−21.5 (−36.8 to −6.2)<0.01
    Negative test results
        Standard PCR743101.4 (96.0 to 113.0)Reference groupReference groupReference group
        Rapid PCR769116.2 (103.4 to 122.6)14.8 (2.4 to 27.1)0.021.4 (−10.8 to 13.5)0.83−1.2 (−14.9 to 12.4)0.86
Subgroup analysis including only patients whose test results were returned during their stay in the hospital
    Regardless of test results
        Standard PCR773126.0 (117.9 to 139.0)Reference groupReference groupReference group
        Rapid PCR1,182104.0 (98.3 to 114.8)−22.2 (−32.5 to −11.9)<0.01−22.8 (−33.1 to −12.5)<0.01−25.5 (−38.1 to −12.9)<0.01
    Positive test results
        Standard PCR175117.5 (100.5 to 142.8)Reference groupReference groupReference group
        Rapid PCR43793.2 (82.2 to 98.6)−24.3 (−42.0 to −6.6)<0.01−27.9 (−45.2 to −10.5)<0.01−33.4 (−49.5 to −17.3)<0.01
    Negative test results
        Standard PCR598129.7 (121.2 to 142.7)Reference groupReference groupReference group
        Rapid PCR745117.9 (109.6 to 125.2)−11.9 (−25.9 to 2.2)0.09−17.3 (−30.4 to −4.3)<0.01−19.6 (−33.7 to −5.5)<0.01
Control group
    201693775.3 (71.0 to 80.5)Reference groupReference group
    20171,10278.9 (73.0 to 87.3)3.2 (−5.6 to 12.1)0.471.6 (−6.0 to 9.2)0.68Not applicable
  • a A negative coefficient indicates a median decrease in the LOS compared to the reference group.

  • b Adjusted for age, study hospital, the source of referral, intensive care admission status, mode of separation, Charlson comorbidity index and type of principal diagnosis. DID (difference-in-difference) = ΔLOS (h) in intervention group − ΔLOS (h) in control group.