ascot trial: clothing to prevent hcp contamination 1149


would have a smaller increase in total contamination compared to control scrubs following a single 12-hour shift in the ICU. Data were summarized using standard statistical methods, as appropriate. Power calculations were performed based on 2 primary


assumptions. First, we assumed that the scrubs used in the control arm would have 2-log increase in total CFU from the beginning to the end of the shift (SD=2).12,13 Second, we assumed a within-nurse, between-shift correlation of 0.5 given the crossover design of the study. Based on these assumptions, we found that 40 subjects and 120 (40 subjects×3 shifts) repeated measures would provide 90% power to determine a mean 1-log decrease (SD=1) in HCP clothing contamination compared to the control. Power calculations were done with 2-sided significance level of 0.025 for each of the 2 primary comparisons. We utilized a generalized estimating equation (GEE) linear


regression model to compare the amount of contamination (log total CFU) between arms at the end of the shift. The model included type of scrubs, log total CFU in the beginning of shift, randomization sequence, patient characteristics (i.e., presence of a percutaneous drain, diarrhea, rectal tube present, or wound; the use of contact precautions; and mechanical ventilation), and total environmental contamination during the shift as covariates. An unstructured working correlation matrix was used. Adjusted mean difference estimates (compared to control) and 95% confidence intervals (CIs) were calculated for each intervention arm. The statistical significance for each of the 2 primary comparisons (each antimicrobial-impregnated scrub vs control) was corrected


for multiple comparisons, and P<.025 was considered statistically significant. Responses to nurse questionnaires were compared using GEE logistic regression with type of scrubs as a covariate using unstructured working correlation matrix. We performed all statistical analyses using SAS version 9.4 software (SAS Institute, Cary, NC).


results Randomized Controlled Trial Results


In total, 41 nurses were enrolled and randomized for study participation. We excluded 1 nurse because she failed to complete all 3 shifts due to illness. A total of 102 unique patients received care from 40 nurse subjects over 120 individual 12-hour ICU shifts and 167 patient encounters for an average of 1.4 patients per nurse per shift. Patients were generally similar across the 3 study arms (Table 1), though 4 of the patient characteristicswere slightly less common in the Scrub 2 arm. In total, 2,919 cultures were obtained from the environment


in patient rooms during the 120 shifts. Environmental contamination was generally similar in the rooms entered by nurses during each arm, though contamination was highest during the control arm (Table 2; supplemental Figure 2). Of the 3 environmental locations tested, bed rails had the highest amount of contamination, followed by beds and supply carts. A total of 2,185 cultures were obtained from HCP clothing


during the 120 shifts. Our primary outcome, the increase in contamination of nurse clothing, was essentially unchanged across the 3 study arms (Table 3; Supplementary Figure 2). The median CFU increase was 61.5 (interquartile range [IQR],


table 1. Characteristics of 102 Unique Patients and 167 Patient Encounters During 120 ICU Shifts in the ASCOT Trial Overall


Characteristic


Median length of hospitalization, d (IQR) Median length of ICU stay, d (IQR) Contact precautions PEG tube present


Percutaneous drain present Diarrhea


Rectal tube present


Mechanical ventilation Wound present


Colonization or infection with target pathogens identified during admission MRSA VRE


MDR Escherichia coli MDR Klebsiella pneumoniae


(N=102), No. (%)a


5.5 (2–15) 3.5 (1–8) 22 (22) 19 (19) 27 (27) 37 (36) 19 (19) 43 (42) 52 (51) 34 (33)


13 (13) 18 (18) 7 (7) 6 (6)


Control (N=57), No. (%)a


9 (2–18) 4 (2–12) 15 (26.3) 15 (26.3) 13 (22.8) 19 (34.5) 11 (19.3) 24 (42) 31 (54) 16 (29)


6 (11) 8 (14) 3 (5) 4 (7)


Scrub 1 (N=57), No. (%)a,b


7 (2–21) 4 (1–13)


12 (21) 18 (32) 13 (23) 24 (42) 9 (16)


29 (51) 36 (63) 15 (29)


4 (8)


7 (14) 2 (4)


5 (10)


Scrub 2 (n=53), No. (%)a,c


5 (1–13) 3 (1–7)


12 (23) 10 (19) 14 (27) 15 (28) 8 (15)


29 (56) 27 (51) 15 (29)


6 (12) 8 (16) 3 (6) 2 (4)


NOTE. IQR, interquartile range; ICU, intensive care unit; MDR, multidrug-resistant; MRSA, methicillin-resistant Staphylococcus aureus;


PEG, percutaneous endoscopic gastrostomy; VRE, vancomycin-resistant enterococci. aUnless otherwise noted for an individual row. Numbers for each arm do not add up to the “overall” column because individual patients were


often encountered in multiple arms. bScrubs contained a complex element compound with embedded silver-alloy. cScrubs impregnated with an organosilane-based quaternary ammonium and a hydrophobic fluoroacrylate copolymer emulsion.


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