Meta-Analysis
Copyright ©The Author(s) 2017.
World J Psychiatr. Mar 22, 2017; 7(1): 60-76
Published online Mar 22, 2017. doi: 10.5498/wjp.v7.i1.60
Table 1 Associations between bullying victimization in children and adolescents and mental health outcomes
Data pointsPooled OR95%CI lower bound95%CI upper boundCochran’s QI² (%)Test for heterogeneity (P value)
Poor mental health
Pooling all391.61.421.81303.7987.49< 0.01
Study type
Retrospective/cross-sectional251.81.442.25211.7888.67< 0.01
Prospective cohort141.391.291.4922.1241.240.05
Sex
Male32.491.863.320.4400.8
Female32.381.4146.9571.220.03
Twins31.411.271.562.520.090.29
Severity of bullying
Sometimes81.51.271.7647.6885.23< 0.01
Frequent81.521.181.9551.486.38< 0.01
Anxiety
Pooling all581.771.342.333816.2398.51< 0.01
Anxiety321.561.391.75434.6192.87< 0.01
Social phobia82.481.593.8611.0136.410.14
Generalised anxiety disorder22.831.385.840.1100.74
PTSD126.411.9321.22497.1197.79< 0.01
Specific phobia12.415.6---
Separation anxiety disorder14.6210.6---
Panic disorder13.11.56.5---
Agoraphobia14.61.712.5---
Study type
Retrospective/cross-sectional392.021.213.383697.4898.97< 0.01
Prospective cohort191.291.061.5584.0378.58< 0.01
Age of bullying
Less than 13 yr131.40.583.41123.1290.25< 0.01
Older than 13 yr451.811.292.563688.8298.81< 0.01
Sex
Male161.841.32.59112.2386.63< 0.01
Female152.461.743.48124.3988.74< 0.01
Severity of bullying
Sometimes71.461.06243.4186.18< 0.01
Frequent252.471.943.14122.4780.4< 0.01
Geographic location and income level
Low-to-middle income222.411.753.32175.9788.07< 0.01
High income361.671.242.253441.1798.98< 0.01
Depression
Pooling all922.211.343.6514525.3299.37< 0.01
Major depressive disorder22.270.687.572.0751.630.15
Study type
Retrospective/cross-sectional631.951.243.072594.9797.61< 0.01
Prospective cohort293.031.316.984583.0599.39< 0.01
Age of bullying
Less than 13 yr362.111.632.72544.993.58< 0.01
Older than 13 yr562.291.244.2313806.7299.6< 0.01
Sex
Male272.071.482.89443.8494.14< 0.01
Female212.131.183.86313.593.62< 0.01
Severity of bullying
Sometimes151.781.392.2878.6182.19< 0.01
Frequent283.262.454.34224.4387.97< 0.01
Geographic location and income level
Low-to-middle income132.531.753.68143.9891.67< 0.01
High income792.151.263.6814351.7299.46< 0.01
Psychotic symptoms
Specific psychiatric symptoms62.071.492.8720.5775.69< 0.01
Non-clinical psychotic experiences92.682.033.5415.147.030.06
Psychotic symptoms52.731.973.7710.8663.160.03
Personality disorders
Anti-social personality disorder20.580.152.282.5360.480.11
Borderline personality disorder32.21.43.464.858.310.09
Eating disorders
Bulimia nervosa131.46.2---
Anorexia nervosa10.0040251---
Non-suicidal self injury
Pooling all301.751.42.19749.0296.13< 0.01
Study type
Retrospective/cross-sectional211.551.092.22721.1597.23< 0.01
Prospective cohort91.651.342.0219.3958.750.01
Sex
Male64.863.357.0713.5663.120.02
Female42.723.658.9266.370.03
Twins22.571.793.70.1200.73
Severity of bullying
Sometimes61.571.092.2534.0485.31< 0.01
Frequent72.521.63.9754.4988.99< 0.01
Suicidal ideation
Pooling all1051.771.562.022093.595.03< 0.01
Study type
Retrospective/cross-sectional861.81.562.092037.4695.83< 0.01
Prospective cohort191.681.382.0538.9853.82< 0.01
Age of bullying
Less than 13 yr221.851.482.374.471.77< 0.01
Older than 13 yr831.751.512.031984.0695.87< 0.01
Sex
Male211.951.642.3276.673.89< 0.01
Female182.151.842.5233.1548.720.01
Severity of bullying
Sometimes161.531.281.8235.1957.38< 0.01
Frequent212.592.063.2549.8359.87< 0.01
Geographic location and income level
Low-to-middle income111.311.061.6160.0283.34< 0.01
High income941.81.432.261894.9195.09< 0.01
Suicide attempt
Pooling all482.131.662.731110.4695.77< 0.01
Suicidal attempt/non-suicidal self injury32.971.685.236.3368.420.04
Study type
Retrospective/cross-sectional402.031.462.841105.6596.47< 0.01
Prospective cohort82.041.383.014.3400.74
Age of bullying
Less than 13 yr112.111.652.6911.4912.980.32
Older than 13 yr371.520.822.83579.7593.79< 0.01
Sex
Male72.931.655.1815.3854.50.02
Female72.891.525.4924.2371.11< 0.01
Severity of bullying
Sometimes92.191.712.87.5200.48
Frequent123.772.555.5828.3161.14< 0.01
Geographic location and income level
Low-to-middle income41.911.073.4322.1886.47< 0.01
High income442.171.692.81084.6196.04< 0.01
Behavioural problems
Pooling all541.371.181.59862.493.85< 0.01
Study type
Retrospective/cross-sectional291.180.991.41311.2191< 0.01
Prospective cohort251.560.942.58413.5394.2< 0.01
Sex
Male91.350.682.67450.0698.22< 0.01
Female71.990.974.188.0793.19< 0.01
Twins21.190.941.57.3186.310.01
Severity of bullying
Sometimes81.950.924.1243.7197.13< 0.01
Frequent82.260.766.69163.5195.72< 0.01
Externalising behaviours201.291.121.5157.0987.9< 0.01
Delinquent/deviant behaviour241.991.243.2423.7894.57< 0.01
Missed school71.490.992.2338.484.37< 0.01
Disruptive behavioural disorders
Attention deficit hyperactivity disorder12.60.88.5---
Oppositional defiant disorder10.80.32.5---
Conduct disorder12.60.88.8---
Other mental health outcomes (not included above)
Nervousness91.821.512.2135.5994.1< 0.01
Powerlessness21.060.951.181.6439.180.2
Feeling low72.261.663.08299.4798< 0.01
Irritability or bad temper71.821.512.2125.0795.2< 0.01
Feel helpless53.22.015.09273.5198.54< 0.01
Feeling tense33.072.064.563.0233.750.22
Unhappy/sad121.250.552.84668.6198.35< 0.01
Worried41.271.091.47314.3599.05< 0.01
Afraid32.681.186.099.4978.920.01