This observational study was conducted at a 120-bed Veterans Affairs (VA) hospital in Temple, TX, on six inpatient units (four acute medical/surgical units and two intensive care units [ICU]). The acute care units are designated as medical telemetry, medical oncology, mixed medical, and mixed medical-surgical. The ICUs are designated as medical and surgical. Continuous 24-h observation was performed separately on each unit by two research team members observing for 8-h sessions to have consistency in observation recordings. The observers followed one healthcare worker (HCW) for their entire shift, documenting surfaces touched (hard surfaces plus bedding and any PME). During the observation period if additional HCWs entered the room to provide care for the patients [physicians, trainees, food and nutrition workers, therapists (physical, occupational and respiratory), environmental services workers, and mid-level providers], their contact with surfaces and equipment were also captured. The HCW was aware of the observation and recording and was asked to go about normal business and care processes when interacting with the patient. However, the HCW was not informed of the specific data being collected or the purpose of the study beyond the general explanation of observing interactions between people and the environment. Research personnel were known by all HCW to be part of the research team and were accustomed to having team members around. Portable medical equipment used in our facility can be broadly categorized into 2 varieties: PME shared among patients regularly such as vital signs machine, COW, Glucometer, bladder scanners; and PME that stays with the patient from admission to discharge such as IV pump/pole, tray table, wound vacuum. In our medical and surgical intensive care units, we have wall mounted computers and vitals recording machines but COWs are available for use.
Summary of observation recordings
A patient encounter was defined as follows: initiated when the HCW entered a patient room and completed when the HCW exited the room after the care episode. An observation was defined as a single touch within an encounter, while a sequence was defined as a string of observations during an encounter. For example, patient to COW then to bedrail & IV pump. Observation data recording was limited to HCW such as nurses, physicians, allied health personnel, housekeeping, and food services; patients and visitors were excluded. Observations were not conducted in bathrooms to protect patient privacy. The observations were recorded sequentially throughout the day on a template designed to document the sequence of touches throughout each patient interaction (see Additional file 1). A touch was defined as any contact event between HCW and patient, surface, or equipment recorded in real time along with the sequence of the touches. If more than one HCW was in the room at the same time, touches were recorded as they occurred and notation made as to HCW 1, 2, or 3 respectively but were combined as one HCW for analysis. Observations were recorded for both contact-isolation and non-isolation rooms.
Data included: (1) surface/medical equipment touched, (2) order of touches, (3) what the equipment was used for in that interaction (e.g., a COW could be used for care documentation on the computer or as a surface work area for IV fluids or medications), (4) whether equipment entered or exited the room – to determine if the equipment is patient dedicated or shared (5) if disinfection of equipment or surfaces took place at any time during this interaction, and (6) if hand hygiene was performed.
A list of frequently touched surfaces (patient, high-touch surface or PME) was created, based on the template data. All surfaces touched by HCWs were documented, including surfaces not explicitly listed on the observation template. Only those surfaces/items that had five or more touches over 24 h were included in the sequence analysis.
Infection prevention activities
The observed activities included donning and doffing of gloves, hand sanitization (either washing with soap and water or using waterless hand sanitizer), and PME disinfection (wiping with disinfectant wipes). This does not factor in discharge or cleaning at change of shift.
Bioburden estimates
To identify the bioburden on the most common PME (COW), all COWs in use across the hospital were sampled by the research team for aerobic bacterial colonies (ABC) and methicillin-resistant Staphylococcus aureus (MRSA) on a single day. The sampling was performed using contact Rodac plates (Hardy Diagnostics, Santa Maria, CA) on the flat table surface and the handle rail of the COW, as well as the scanner used for the medication administration system. The surface area for ABC was 25cm2 and for MRSA was 75 cm2. The sampling method, incubation, and identification of the organisms are described elsewhere [15].
Analysis
The average number of touches per encounter was calculated for each surface type and inpatient unit. Sequences were also separated by whether hand hygiene (glove or hand sanitization) occurred (yes/no), and by room access: upon room entry, during the sequence, or upon room exit. We combined the two because both these events potentially represented reduced transmission risk. The observations of touches were recorded as a sequence of events analyzed with sequence analysis software and visually represented by network plots. The network analysis was completed using the package ‘igraph’ in R version 3.2.3 [16]. The sequences were also analyzed for common sub-sequences that might indicate unique/important patterns in HCW interactions with the patient and the environment. This information is visually quantified by the network plots and provides additional details on the characteristics of individual sequences. Sequence mining and analysis were completed using the package ‘TraMineR’ in R version 3.2.3 [17, 18].