modified reporting of urine culture 815
methods Trial Design
The study was a randomized, parallel, superiority trial com- paring 2 different methods of reporting positive urine cultures. Eligible urine specimens were inoculated onto blood and MacConkey agars, incubated overnight, and interpreted quantitatively according to laboratory protocol. There were no changes to the trial design during the study.
Participants
Consecutive positive urine cultures were assessed. Specimen eligibility was assessed prospectively using medical records.We used the following exclusion criteria: age <18 years, preg- nancy, indwelling catheter, receiving antibiotics at the time of collection, absolute neutrophil count <1×109 per liter, admission to the intensive care unit. Specimens were collected from inpatients admitted to 1 of
the 2 tertiary-care academic hospitals in St John’s, New- foundland, Canada. The Health Sciences Center (346 acute- care beds) provides medicine, pediatric and surgery inpatient services, critical care, cardiac surgery, neurosurgery, plastic surgery, burn treatment, obstetrics/gynecology, and acute psychiatry. St Clare’s Mercy Hospital (205 acute-care beds) provides medicine and surgical inpatient services, critical care, general surgery, vascular surgery, thoracic surgery, otolar- yngology, orthopedics, and ambulatory services. The metro- politan area of St John’s has a population of 219,000 people (2017). One centralized microbiology laboratory performs all testing for the city, reporting ~30 positive urine cultures per day.
Intervention
Enrolled microbiology laboratory reports were randomized equally into standard report (control) or modified report (intervention) arms before being released to physicians via the electronic health record (Meditech). The only laboratory report made available to physicians in the electronic health record on the included specimen was the study report. Speci- mens randomized to the standard report arm were reported using the usual format, including bacterial count, bacterial identification, and antibiotic susceptibility. The modified report informed the physician that significant
report was immediately provided in the electronic health record. After randomization and reporting, included patients were
assessed by an investigator on the day of reporting, using medical records, to determine the clinical diagnosis of either UTI or ASB, based on diagnostic criteria for noncatheterized urine specimens.5 For treatment decisions and adverse events, medical records were again assessed at 72 hours and at 7 days after culture reporting. Investigators did not communicate with attending physicians. If patients were discharged during the follow-up period, primary care physicians were contacted by telephone to collect adverse event data. Calls received by the laboratory requesting complete reports were recorded.
Outcomes
The primary efficacy outcome was the proportion of appro- priate antibiotic treatment prescribed based on diagnosis (ASB or UTI) as determined by investigators and treatment pre- scribed within 24 hours in response to the laboratory result. Appropriate treatment was defined as no antibiotic given for ASB (untreated ASB) or any antibiotic given for UTI (treated UTI), and inappropriate treatment was defined as any anti- biotic given for ASB (treated ASB) or no treatment given for UTI (untreated UTI). The primary safety outcome was bacteremia rate. Secondary efficacy outcomes were rate of requests for complete reports, and cost savings. Secondary safety outcomes were deaths and adverse events, defined as evidence of systemic inflammatory response syndrome (SIRS) at 72 hours (vital signs, glucose, positive fluid balance, and changes in mental status) or any new symptoms during 7 days after urine collection. The intervention was a single time event; therefore, once randomized and reported, specimens could not discontinue the intervention. If a physician requested standard reporting after receiving a modified report, the patient was analyzed as randomized and included in follow-up.
Sample Size
bacterial growth was detected, but bacterial identification and susceptibility information were withheld unless requested. Specimens randomized to the modified report were reported as: “This POSITIVE urine culture may represent asymptomatic bacteriuria or urinary tract infection. If urinary tract infection is suspected clinically, please call the microbiology laboratory at [phone] between 0900 to 2300, or the microbiology tech- nologist on-call at [phone] at night, for identification and susceptibility results.” If a request was received, the complete
The expected rate of inappropriate treatment was 45% in the standard reporting arm and 15% in the modified reporting arm.3 A power analysis for χ2 test of proportions, with a risk of type 1 error of 5%, and type 2 error of 20%, suggested a sample size of 84 patient results. Allowing for attrition and losses to follow-up of 25%, 110 consecutive inpatient samples were recruited.
Interim Analysis and Stopping Rules
One interim analysis was performed after the recruitment of 47 specimens. There was no predefined stopping rule. The study was stopped after the planned sample size was recruited.
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40 |
Page 41 |
Page 42 |
Page 43 |
Page 44 |
Page 45 |
Page 46 |
Page 47 |
Page 48 |
Page 49 |
Page 50 |
Page 51 |
Page 52 |
Page 53 |
Page 54 |
Page 55 |
Page 56 |
Page 57 |
Page 58 |
Page 59 |
Page 60 |
Page 61 |
Page 62 |
Page 63 |
Page 64 |
Page 65 |
Page 66 |
Page 67 |
Page 68 |
Page 69 |
Page 70 |
Page 71 |
Page 72 |
Page 73 |
Page 74 |
Page 75 |
Page 76 |
Page 77 |
Page 78 |
Page 79 |
Page 80 |
Page 81 |
Page 82 |
Page 83 |
Page 84 |
Page 85 |
Page 86 |
Page 87 |
Page 88 |
Page 89 |
Page 90 |
Page 91 |
Page 92 |
Page 93 |
Page 94 |
Page 95 |
Page 96 |
Page 97 |
Page 98 |
Page 99 |
Page 100 |
Page 101 |
Page 102 |
Page 103 |
Page 104 |
Page 105 |
Page 106 |
Page 107 |
Page 108 |
Page 109 |
Page 110 |
Page 111 |
Page 112 |
Page 113 |
Page 114 |
Page 115 |
Page 116 |
Page 117 |
Page 118 |
Page 119 |
Page 120 |
Page 121 |
Page 122 |
Page 123 |
Page 124 |
Page 125 |
Page 126 |
Page 127 |
Page 128 |
Page 129 |
Page 130 |
Page 131 |
Page 132 |
Page 133 |
Page 134 |
Page 135 |
Page 136 |
Page 137 |
Page 138 |
Page 139 |
Page 140 |
Page 141 |
Page 142 |
Page 143 |
Page 144
