Test volume

Page last updated: 15 May 2013

The volume of pathology tests ordered by clinicians varied greatly between hospitals. These differences are not necessarily driven by factors associated with patient acuity or by the type of medical service.32 Table 9 compares the mean number of tests ordered for each test order episode for each year from 2008 to 2011 when EMR was introduced at each of the hospitals. It shows that the overall mean rates of tests per test ordering episode were uniformly and consistently lower across all six study hospitals in 2011 (after the introduction of EMR) than in 2008, independent sample t-tests found the difference significant in all hospitals.

 Year Hospital 2008 2009 2010 2011 Mean Difference: 2008 - 2011 A 4.68 4.20 4.51 4.62 0.06 t(77447.1)=2.37, p<.05 B 3.16 3.03 3.07 3.09 0.07 t(20585.3)=2.08, p<.05 C 4.42 3.91 4.19 4.15 0.27 t(24647.7)=2.95, p<.001 D 4.70 4.14 3.98 4.35 0.36 t(20726.1)=7.62, p<.001 E 4.65 4.17 4.33 4.49 0.16 t(100742.4)=7.26, p<.001 F 5.04 4.32 4.38 4.32 0.72 t(70372.9)=26.39, p<.001 Overall 4.63 4.11 4.27 4.36 0.27 t(317634.6)=21.72, p<.001

Independent sample t-tests
Table 9. A comparison, between years, of the mean number of tests ordered in each test order episode at the six study hospitals. Numbers in normal text are pre-EMR implementation; numbers in bold are post-EMR implementation; numbers in italics are overall rates.

A comparison of the mean number of tests per admission and mean length of stay between the six study hospitals and across the four years is shown in Table 10. A comparison of the mean number of tests per admission, at each hospital, for the periods before and after the availability of electronic ordering, reveals an inconsistent pattern of results. Hospitals A and E showed an increase in the number of tests per patient admission, whereas Hospitals C and D showed a reduction in the mean tests per patient admission. Lastly, the rate at Hospitals B and F was similar in 2011 to what it was in 2008. The mean length of stay was, however, shorter at all hospitals in 2011 compared to 2008.
 Mean Number of Tests Per Admission (Number of Tests/Number of Admissions) Mean Length of Stay (hours) Hospital 2008 2009 2010 2011 A 19.91 (75172/3776) 181 19.51 (70036/3589) 191 19.57 (71714/3665) 189 20.15 (76795/3812) 163 B 7.22 (8560/1185) 128 7.98 (9068/1137) 131 7.37 (7938/1077) 118 7.35 (8053/1096) 115 C 16.26 (21851/1344) 110 18.29 (24121/1319) 117 15.80 (22568/1428) 98 14.97 (21511/1437) 95 D 13.53 (24172/1787) 101 13.19 (24037/1822) 88 13.17 (24160/1835) 90 12.61 (26262/2083) 86 E 19.17 (98553/5141) 146 20.76 (102565/4941) 141 20.77 (108502/5224) 138 22.41 (119276/5322) 143 F 17.35 (75958/4377) 134 18.34 (72151/3935) 156 15.81 (78686/4977) 122 17.28 (84370/4882) 130

Table 10. A comparison, between years, of the mean number of pathology tests ordered in each patient admission, at each of the six study hospitals. Numbers in normal text are pre-EMR implementation; numbers in bold are post-EMR implementation.