| Risk factor category | Cohort (country) author, year | Outcome variable | Exposure variable | Effect estimate (95% CI) | |
| Comparison group | Reference group | ||||
| Individual risk factors | |||||
| Sex | NLSCY (Canada), Soubhi 200418 | Risk of any injury 4–11 years | Boys | Girls | OR = 1.56 (1.35 to 1.85) |
| Baise City, (China) Chen, 200513 | Risk of any injury aged 11–18 years | Boys | Girls | OR = 1.25 (1.02 to 1.53) | |
| Eastern Shore, (USA) Alexander, 199222 | Risk of injury whilst in 9th grade (∼14–15 years) | Boys | Girls | OR = 1.96 (1.26 to 3.04) | |
| South Wales, (UK) Davidson, 198839 | Risk of injury at 5–8 years | Boys | Girls | RR = 1.52 (1.23 to 1.88) | |
| Kamphaeng Phet Province (Thailand), Kozik, 199920 | Risk of having a motor vehicle crash while enrolled in school | Boys | Girls | RR = 1.4 (1.2 to 1.6) | |
| Age | Baise City, (China) Chen, 200513 | Risk of any injury | 11–13-year-olds | 17–18-year-olds | OR = 1.51 (1.00 to 2.26) |
| 14–15-year-olds | 17–18-year-olds | OR = 2.94 (1.96 to 4.42) | |||
| Ethnicity | Baise City, (China) Chen, 200513 | Risk of any injury aged 11–18 years | Students from minority ethnic groups | Students from one of the main ethnic groups | OR = 1.67 (1.05 to 2.66) |
| Growth | DMCDS, (NZ) Jones, 200438 | Risk of any fracture 5–18 years | Children with a standard deviation increase in mean weight | Mean weight at age 3 | RR = 1.14 (1.03 to 1.27)* |
| Children with a standard deviation increase in mean height | Mean height at age 3 | RR = 1.13 (1.01 to 1.23)* | |||
| Children with a standard deviation increase in mean weight | Weight at ages 5–18 years | RR = 1.15 (1.03 to 1.28)* | |||
| Children with a standard deviation increase in mean height | Height at ages 5–18 years | RR = 1.13 (1.02 to 1.24)* | |||
| Risk of prepubertal fractures | Children with a standard deviation increase in mean birth length | Mean birth length | RR = 1.28 (1.04 to 1.58)* | ||
| Children with a standard deviation increase in BMI | BMI aged 5–18 years | RR = 1.24 (1.02 to 1.52)* | |||
| Sensory deficit | NCDS, (UK) Pless, 198952 | Risk of road traffic injuries at 7–11 years | Boys with sensory deficit | Boys without sensory deficit | OR = 1.54 (1.1 to 2.1) (Girls had CI crossing 1.0) |
| NCDS, (UK) Rahi, 200653 | Risk of injury at 7–11 years | Children with resolved amblyopia (Note: small numbers) | Children with normal vision | OR = 0.33 (0.12 to 0.89) | |
| Coordination/motor skills | NCDS, (UK) Pless, 198952 | Risk of road traffic injuries at 7–11 years | Girls with poor gross motor control | Girls with normal gross motor control | OR = 1.68 (1.1 to 2.6) (Boys had CI crossing 1.0) |
| Eastern Shore, (US) Alexander, 199222 | Risk of injury when in 10th grade | Children playing 1–3 team sports in previous 12 months | Children not playing team sports in previous 12 months | OR = 1.66 (1.11 to 2.57) | |
| CSDD, (UK) Shepherd, 200248 | Risk of injury at 16–18 years | Boys with “low” heart rate at 16–18 years (rate unspecified) | Boys without low heart rate | OR = 1.72 (1.14 to 2.60) | |
| Concentration and attention | NCDS, (UK) Pless, 198952 | Risk of road traffic injuries at 7–11 years | “Fidgety” boys (parental report) | Boys not considered “fidgety” | OR = 1.67 (1.2 to 2.4) (Girls had CI crossing 1.0) |
| Psychological difficulties | South Wales, (UK) Davidson, 198839 | Risk of injury at 5–8 years | Children with marked fears | Children without marked fears | RR = 1.95 (1.35 to 2.83) |
| NCDS, (UK) Pless, 198952 | Risk of road traffic injuries at age 7 years | “Sensitive” boys (parental report) | Boys not reported “sensitive” | OR = 1.38 (1.1 to 1.8) (Girls had CI crossing 1.0) | |
| “Maladjusted” girls (parental report) | Girls not reported “maladjusted” | OR = 1.8 (NS) | |||
| Maanshan City, (China) Peng, 200314 | Risk of injury at age 7–13 years | Neurotic behaviour (parental report) | Child not reported neurotic | RR = 1.96 (1.36 to 2.82) | |
| Baise City, (China) Chen, 200512 | Risk of injury at 13–18 years | Self-reported somatisation | Children with low somatisation score | OR = 2.00 (1.52 to 2.63)† | |
| Self-reported obsessive-compulsiveness | Children with low obsessive-compulsiveness score | OR = 2.10 (1.71 to 2.58)† | |||
| Self-reported anxiety | Children with low anxiety score | OR = 2.08 (1.62 to 2.66)† | |||
| Self-reported depression | Children with low depression score | OR = 2.00 (1.59 to 2.51)† | |||
| Self-reported interpersonal-sensitivity | Children with low interpersonal-sensitivity score | OR = 1.66 (1.34 to 2.06)† | |||
| Self-reported psychoticism | Children with low psychoticism score | OR = 1.60 (1.26 to 2.03)† | |||
| Behavioural difficulties | Maanshan City, (China) Peng, 200314 | Risk of injury at age 7–13 years | Parent-reported antisocial behaviour | Children without antisocial behaviour | RR = 2.04 (1.37 to 3.01) |
| Add Health study, (USA) Hammig, 200119 | Risk of injuring self between 11–18 years | Self-reported group fighting 3+ times in past 12 months | No group fighting or group fighting 1–2 times | OR = 1.97 (1.1 to 3.5) | |
| Self-reported fighting with a stranger in past 12 months | No fighting with strangers | OR = 2.01 (1.3 to 3.1) | |||
| Risk of injuring others when aged 11–18 years | Self-reported group fighting 1–2 times in past 12 months | No group fighting | OR = 2.51 (1.8 to 3.5) | ||
| Self-reported group fighting 3+ times in past 12 months | No group fighting or group fighting 1–2 times | OR = 5.67 (3.2 to 10.0) | |||
| Self-reported fighting with a stranger in past 12 months | No fighting with strangers | OR = 1.69 (1.2 to 2.4) | |||
| Self-reported use of a weapon | No weapon use | OR = 2.24 (1.4 to 3.7) | |||
| CSDD, (UK) Shepherd, 200248 | Risk of injury at 16–18 years | Boys who were antisocial (teacher report) | Boys not reported to be antisocial | OR = 1.93 (NS) | |
| Risk of injury in an assault at 16–18 years | Boys who engaged in troublesome behaviour (teacher report) | Boys who did not engage in troublesome behaviour | OR = 4.36 (2.01 to 9.46) | ||
| South Wales, (UK) Davidson, 198839 | Risk of injury at 5–8 years | Children with discipline problems | Children without discipline problems | RR = 1.29 (1.04 to 1.60) | |
| Personal risk-taking behaviour | CSDD, (UK) Shepherd, 200248 | Risk of injury at 16–18 years | Boys who engaged in “daring” behaviour (parent report) | Boys who did not engage in “daring” behaviour | OR = 3.20 (1.49 to 6.90) |
| DMCDS, (NZ) Jones, 200438 | Risk of fracture | Personal daily smoking in teenagers | Not smoking, or occasional smoking | RR = 1.43 (1.05 to 1.95) | |
| Eastern Shore, (US) Alexander, 199222 | Risk of injury while in 9th grade (∼14–15 years) | Self-report of lifetime marijuana use 1–5 times | Not having taken marijuana | OR = 2.03 (1.11 to 3.71)‡ | |
| Risk of injury while in 10th grade (∼15–16 years) | Self-report of alcohol use on 1–2 days in previous 30 days | No alcohol use in previous 30 days | OR = 1.69 (1.05 to 2.71)‡ | ||
| Self-report of alcohol use on 3 or more days in previous 30 days | No alcohol use in previous 30 days | OR = 1.74 (1.07 to 2.84)‡ | |||
| Employment | Eastern Shore, (US) Alexander, 199222 | Risk of injury while in 9th grade (∼14–15 years) | Self-report of working ⩾11 h/week | Working none or less than 11 h/week | OR = 2.37 (1.26 to 4.45) |
| Previous injuries | CHES, (UK) Bijur, 198842 | Risk of injuries at 5–10 years | Children having 3 or more injuries before 5 years of age | Children having no injuries before the age of 5 years | RR = 5.9 (4.4 to 8.8) |
| Risk of injuries requiring hospitalisation at 5–10 years | Children admitted to hospital 1 or more times for injuries before 5 years of age | Children not admitted to hospital for injuries before 5 years of age | RR = 2.5 (2.0 to 3.3) | ||
| Family risk factors | |||||
| Family size | CHES, (UK) Bijur, 198844 | Risk of injuries requiring hospitalisation at 5–10 years | Children living in a household with 4 or more children | Children living in a household with 1–3 children | OR = 1.91 (1.16 to 3.12)¶ |
| South Wales, (UK) Davidson, 198740 | Risk of injury at 5–8 years | Children living in household with 1–2 children | Children living in household with more than 2 children | RR = 0.58 (0.38 to 0.89) | |
| CSDD, (UK) Shepherd, 200248 | Risk of injury in an assault at 16–18 years | Children living in a large family at 8–10 years | Children not living in a large family at 8–10 years | OR = 2.89 (1.33 to 6.26) | |
| Young maternal age | Maanshan City, (China) Peng, 200314 | Risk of injury at 7–13 years | Having a mother aged 22 years or younger at birth of study child | Having a mother older than 22 years at birth of study child | RR = 2.25 (1.04 to 4.72) |
| Parent figure | NCDS, (UK) Pless, 198952 | Risk of road traffic injuries at 12–16 years | Boys not living with natural mother at age 11 | Boys living with natural mother | OR = 1.98 (1.1 to 3.5) |
| Family income | CSDD, (UK) Shepherd, 200248 | Risk of being injured in an assault at age 16–18 years | Children from families with low incomes | Children from families not on low incomes | OR = 3.09 (1.42 to 6.70) |
| Baise City, (China) Chen, 2005a13 | Risk of injury at 12–19 years | Adolescents from family in middle income band | Adolescents from family in lowest income band | OR = 1.42 (1.11 to 1.81) | |
| Parental education | Maanshan City, (China) Peng, 200314 | Risk of injury at 7–13 years | Child’s mother had “high” level of education (unspecified) | Child’s mother did not have “high” level of education | RR = 1.23 (1.07 to 1.33) |
| Parenting ability and activity | NLSCY (Canada), Soubhi 200418 | Risk of injury at 4–11 years | Children with below average consistency of parenting | Children with average or above average consistency of parenting | OR = 1.43 (1.22 to 1.68)§ |
| Maanshan City, (China) Peng, 200314 | Risk of injury at 7–13 years | Children with poor injury-prevention activity at home | Children with adequate or good injury-prevention activity at home | RR = 1.33 (1.03 to 1.71) | |
| Children whose parents accompanied them to school | Children who were unaccompanied to school | RR = 0.71 (0.06 to 0.87) | |||
| Family dysfunction | NCDS, (UK) Pless, 198952 | Risk of road traffic injury at age 7–11 years | Boys who appeared to be “scruffy and underfed” (teacher report) at age 7 years | Boys who were not “scruffy and underfed” | OR = 1.69 (1.1 to 2.7) |
| Boys who had ever been in care of social services | Boys never taken into care of social services | OR = 1.64 (1.1 to 2.9) | |||
| Girls from homes with “family problems” | Girls from homes without “family problem” | OR = 2.00 (1.3 to 3.1) | |||
| Boys who were “fidgety” and in care of local authority | Boys not “fidgety” or in care of local authority | OR = 1.8 (NS) | |||
| Risk of road traffic injury at age 12–16 years | Boys who appeared to be “scruffy and underfed” (teacher report) at age 11 | Boys who were not “scruffy and underfed” | OR = 1.99 (1.1 to 3.4) | ||
| Boys who had ever been in care of social services | Boys never taken into care of social services | OR = 2.22 (1.3 to 3.7) | |||
| Girls from homes with “family problems” | Girls from homes without “family problems” | OR = 1.64 (1.1 to 2.4) | |||
| Girls who were “fidgety” and living in a crowded home | Girls not “fidgety” or in crowded home | OR = 1.56 (NS) | |||
| Environmental risk factors | |||||
| Physical home environment | NCDS, (UK) Pless, 198952 | Risk of road traffic injury at age 7 years | Boys living in homes lacking basic amenities | Boys living in homes with basic amenities | OR = 1.37 (1.1 to 1.8) |
“Greater than by chance” indicates studies where 95% CIs do not contain OR = 1.00 or RR = 1.00, or where p values are <0.05.
*Adjusted for sex and age.
†Adjusted for sex, age and ethnicity.
‡Adjusted for sex, race and parents educational level.
¶Adjusted for family socioeconomic status, family income, housing quality, maternal mental health, maternal education, maternal employment, family structure, child aggression, child independence and child overactivity.
§Adjusted for socioeconomic status, the number of people in the household, caregiver’s physical and mental health, and a history of injury.
BMI, body mass index; CHES, Child Health and Education Study; CSDD, Cambridge Study of Delinquent Development; DMCDS, Dunedin Multidisciplinary Child Development Study; NCDS, National Child Development Study; NLSCY, National Longitudinal Study of Children and Youth; NS, not stated.