Study setting and population
Our study population comprised of medical doctors and nurses working in an ICU in the year 2015. The medical doctor and nurse could work in the same ICU and more than one reply was possible from one unit.
An ICU was defined as a unit meeting all of the following criteria: provides facilities for invasive mechanical ventilation, and pump-controlled administration of infusion, functions 24 h a day and 7 days a week, and there is at least one doctor immediately available at all times to deal with emergencies.
Questionnaire
An online questionnaire was developed and consisted of five parts: 1) Characteristics of the respondent and ICU setting, 2) Clinical practices for CL insertion, 3) Clinical practices for CL maintenance, 4) Monitoring of outcomes and processes and 5) Attitudes towards measurement as a tool for improvement. We used as a reference clinical practice guidelines published by the Society for Healthcare Epidemiology of America (SHEA) [4]. We included questions on the measurement of outcomes (CLABSI rate and the ability to report selected indicators) and measurement of processes such as compliance with prevention practices, including hand hygiene, and the device utilization ratio (ratio of central-line days to patient-days). Attitudes regarding the implementation of a data collection system was measured using a 5 point-Likert scale (1: strongly agree, 5: strongly disagree) [17, 18].
The questionnaire was developed and pretested in English and translated into 9 languages (Spanish, German, Portuguese, Italian, French, Dutch, Russian, Mandarin and Japanese). Native speaker intensive care doctors and/or infection control practitioners translated the questionnaire. Each translation was independently verified by a second native speaking physician. Participation was anonymous.
We used Limesurvey ® 2.0, an open source web survey application, to collect the data [19].
Dissemination to target group
The questionnaire was available online from 10 June 2015 to 31 October 2015. It was endorsed by 5 international societies (the European Society of Intensive Care Medicine (ESICM), the Society of Critical Care Medicine (SCCM), the World Federation of Societies of Intensive Care and Critical Medicine (WFSICCM), the International Symposium on Intensive Care and Emergency Medicine (ISICEM) and the Middle East Critical Care Assembly (MCCA)), and one national society (Japanese society of intensive care medicine (JSCIM)). Endorsement implied mailing to members; and/or posting on the website. We also identified and contacted national ICU societies who advertised the questionnaire on their website and pertaining congresses, and developed mass mailings to all its members.
Sample size
No sample size or power calculations were conducted.
Data analysis
Descriptive statistics were used to summarize characteristics of the study population Standard errors were calculated by dividing the standard deviations of each estimate by the square root of the sample size (n).
Based on the 2015 World Bank classification [20] we categorized countries as low, middle and high- income. We computed weighted estimates for middle and high-income countries using total country population [20] as the weight (to correct for contributing responses from each country) for those that provided at least 10 completed replies (arbitrary cut-off).
Analyses were conducted using STATA 13 (svyset and svy commands for survey data for weighted estimates).
Detailed country specific data are available as a Additional file 1. Data are freely available and have been deposited in the Dryad Digital Repository: http://dx.doi.org/10.5061/dryad.f7h12
Further use and exploitation of these data is encouraged.