Table 1

Eligibility criteria following the PECOS scheme

Criterion	Inclusion	Exclusion
Participants	Certified HCWs Apprentice HCWs	All other than certified or apprentice HCWs, including cleaning personnel
Exposure	Working as active HCW	n/a
Comparator	n/a	n/a
Outcome	Prevalence of HE (ie, proportion of HCWs who have HE at a specific period of time, for example, current HE (point prevalence), HE in the past 12 months (1-year prevalence), and HE ever (lifetime prevalence)), both clinically assessed as well as self-reported HE based on questions in the style of the NOSQ-2002.24	Skin changes/adverse skin event/symptom-based diagnosis
	Incidence of HE (ie, occurrence of new HE cases in HCWs during a given time period which will be reported as number of new cases per 1000 person years) both clinically assessed as well as self-reported HE based on questions in the style of the NOSQ-2002.24 In cross-sectional study designs, the incidence can be assessed by retrospective questions (ie, ‘Have you newly developed HE?’ in a given time period).	Skin changes/adverse skin event/symptom-based diagnosis
	HE severity (measured by, eg, HECSI,25 OHSI,26 PGA or other validated instruments (eg, photographic guide) as well as self-reported or by using undefined categories such as ‘mild’, ‘moderate’ or ‘severe’	n/a
	Prevalence of clinically assessed (eg, clinical diagnosis, UK Working Party’s diagnostic criteria,27 Hanifin and Rajka diagnostic criteria for AD28 as well as self-reported AD (eg, ‘Have you ever had childhood eczema?’, ‘Have you ever had an itchy rash that has been coming and going for at least 6 months, and at some time has affected skin creases?’)29	Other instruments
Study design	Experimental studies	Qualitative studies
	Observational studies	Reviews
	Survey-based studies	Case reports
	Clinical studies	Case series

HCW(s), healthcare worker(s) who provide healthcare services such as care and treatment including nurses, nursing auxiliaries, midwives, physicians, physician assistants and other clinicians (eg, physiotherapists, occupational therapists etc), excluding, for example, cleaning personnel.
AD, atopic dermatitis; HCWs, healthcare workers; HE, hand eczema; HECSI, Hand Eczema Severity Index; n/a, not applicable; NOSQ-2002, Nordic Occupational Skin Questionnaire; OHSI, Osnabrück Hand Eczema Severity Index; PGA, Physician Global Assessment.