Supplementary material 4.Details on the study population.

Clinical data could be extracted from documentation for a total of 119 of the 160assessed patients (74.4%). Among these 119 patients assessed in more detail, 17 showed discrepant results for the two schemes regarding nasal colonization and 14 regarding pharyngeal colonization.

The numbers were too small for statistical assessments and are thus descriptively assessed. There is a tendency of a higher rate of discrepancy between the schemes if antibiotic therapy prior to control swabbing was reported. The study was not powered for subgroup analyses and the low number of cases makes any interpretation challenging.

The low number of reported invasive devices suggests underreporting in the assessed case files.

Study participants with available clinical data / Study participants with available clinical data and discrepant results for the two schemes regarding nasal colonization / Study participants with available clinical data and discrepant results for the two schemes regarding pharyngeal colonization
Total number (n) / 119 / 17 / 14
Female sex (number / percent) / 46 / 38.7% / 5 / 29.4% / 7 / 50.0%
Age (mean ± standard deviation; median) / 70.6 ± 13.5, 74 / 73.6 ± 15.1; 76 / 72.9 ± 11.5; 72
Department (number / percent) / Internal Medicine (49 / 41.2%); Surgery (19 / 16.0%); Radiation therapy (16 / 13.4%); Intensive Care Unit (15 / 12.6%); Neurology (8 / 6.7%); Urology (6 / 5.0%); Ear-Nose-Throat (2 / 1.7%); Dermatology & Ophthalmology & Orthopedics & Psychiatry (1 / 0.8% each) / Internal Medicine (6 / 35.3%); Radiation therapy (4 / 23.5%); Intensive Care Unit (3 / 17.6%); Surgery (2 / 11.8%); Neurology & Urology (1 / 5.9% each) / Internal Medicine (6 / 42.9%); Radiation therapy (3 / 21.4%); Neurology & Urology (2 / 14.3% each); Surgery 1 (7.1%)
Concomitant infections with MRSA (number / percent) / 14 / 11.8% / 4 / 23.5% / 2 / 14.3%
Sites of infections (number) / unknown focus (n=5); urinary tract infection (n=4); wounds (n=3); blood culture (n=1); cartilage (n=1) / Urinary tract infection (n=2); wound (n=1); cartilage (n=1) / Urinary tract infection (n=1); wound (n=1)
No antibiotic therapy at all reported (number / percent) / 86 / 72.3% / 4 / 28.6% / 9 / 64.3%
Antibiotic therapy prior to control swabbing reported (number / percent) / 14 / 11.8% / 10 / 58.9% / 3 / 21.4%
Antibiotic therapy during control swabbing reported (number / percent) / 19 / 16.0% / 3 / 17.6% / 2 / 14.3%
Main diagnosis groups (number / percent) / Infection (31 / 26.1%); cardio-vascular disease (28 / 23.5%); tumor (27 / 22.7%); metabolic disorder (15 / 12.6%); trauma & neuro-psychiatric disease (6 / 5.0% each); immunological disease (5 / 4.2%); ophthalmological disease (1 / 0.8%) / Tumor (5 / 29.4%); infection & cardio-vascular disease (4 / 23.5% each); metabolic disorder (3 / 17.6%); immunological disorder (1 / 5.9%) / Infection & metabolic disease (4 / 28.6% each); tumor & neuro-psychiatric disease (3 / 21.4% each)
Nasal MRSA colonization (number / percent) / 105 / 88.2% / Not applicable (assessment parameter) / 13 / 92.9%
Pharyngeal MRSA colonization (number / percent) / 87 / 73.1% / 11 / 64.7% / Not applicable (assessment parameter)
Nasogastric line reported (number / percent) / 1 / 0.8% / 1 / 5.9% / 0 / 0%
Ulcers reported / 5 / 4.2% / 0 / 0% / 0 / 0%
Central venous line reported / 11 / 9.2% / 2 / 11.8% / 0 / 0%
Other catheters reported (number / percent / kind of device) / 15 / 12.6% / urinary tract catheter (n=13); arterial catheter (n=9); drain of the thorax (n=3); drain of the pleura (n=2); percutaneous endoscopic gastrostomy (n=1) / 3 / 17.6% / urinary tract catheter (n=3); arterial catheter (n=2) / 1 / 7.1% / urinary tract catheter (n=1)
Matching of the two swabbing schemes regarding the nose / 102 / 85.7% / Not applicable (assessment parameter) / 12 / 85.7%
Matching of the two swabbing schemes regarding the pharynx / 102 / 85.7% / 14 / 82.4% / Not applicable (assessment parameter)