Table 1. Study characteristics of studies meeting eligibility criteria for data synthesis.

Author(s)	Year	Country	Study design	Frequent attendance definition	Sample	Main outcomes
Garralda et al 14	1998	UK	Cross-sectional	≥4 attendances in 12 months	109 frequently attending children aged 7–12 years, registered with 2 practices	21% of children accounted for 58% of all attendances in 12 months.Disordered children had educational difficulties and problems in social relationships, and came from dysfunctional homes.
Vila et al 15	2012	UK	Cross-sectional	≥4 attendances in 12 months	1116 secondary school pupils	30% were frequent attenders.Frequent attenders were younger; more likely to come from lower socioeconomic backgrounds; reported physical problems; had more hospital visits; had more recent intense somatic symptoms, made worse by stress and causing impairment; had more days off school; had presence of emotional symptoms and a history of mental health consultations; were more likely to see a hospital doctor; and had current illness.
Fosarelli et al 19	1987	US	Prospective cohort	Low usage 0–4 visit/years;medium usage 5–6 visit/years;high usage ≥7 visit/years(Different thresholds were used for subsequent years)	293 infants to 3 years old attending hospital-based primary care clinic	Frequent users of one facet of care remained frequent users of other facets for all of 3 years. Children who used the clinic more frequently were more likely to have registered before 1 month of age, have multiple chronic conditions, and demonstrate consistently frequent use for health maintenance throughout the 3 years. Frequent users were also more likely to have zero or one sibling.
Stojanović-Špehar et al17	2007	Croatia	Retrospective cohort	>75 th percentile of consultation frequency	964 preschool children (1–6 years of age) from 6 family practices, and a paediatric clinic	255 were frequent attenders, with a median visit frequency of 10/year.Age of child (2–3 years), and certain symptoms and conditions (infectious, respiratory, and dermatological conditions) were associated with frequent attendance, and parents of frequent attenders were more likely to have secondary education. Those seen by a paediatrician were also more likely to be frequent attenders.
Shraim et al 16	2014	UK	Prospective cohort	Once in year 1, and at least once in the following year.	1437children (2–16 years) registered with primary practices contributing to a primary care database, who saw a doctor for non-specific physical symptoms in 2009	27% of children (n = 390) had repeated consultations for non-specific physical symptoms. Consultations for any non-specific physical symptoms in mothers was associated with increased risk of repeated consultations for non-specific physical symptoms among children.
Martin et al 18	2018	Spain	Cross-sectional questionnaire survey	>90th percentile/ ≥6 visits in the last 6 months	346 children (6 months–14 years) attending paediatric clinics in 2 urban primary care centres	33 high frequency users of primary care services (n = 55 when emergency or urgent care services included) identified.Younger age of child (<2) and higher anxiety levels in parents (GADS≥4) were related to being frequent users of primary care clinics.

GADS = Goldberg Anxiety and Depression Scale