Abstract, Title and References:

The aim is clear. The aim has been written as : to identify multiple risk factors and designing appropriate intervention programs to reduce or prevent bullying among children and adolescents. The methods and results sections have been explained in the abstract as separate sections. Data were collected twice in 2004 and 2007 by using questionnaire among the study population aged 14-15 years (baseline) and 17-18 years (end-line). The risk factors were analyzed at individual and societal level. National register was also reviewed to get information on social background of participants. Various risk factors were identified for being bullied at school and at work such as being obese, low self-assessed position in school class, overprotective parents, low self-esteem, low sense of coherence and low socioeconomic status were risk factors for being bullied at school. Likewise, being overweight, smoking, low self-assessed position in class, low sense of coherence and low socioeconomic status were risk factors for being bullied at work. The title seems incomplete as it doesn't describe fully on what is to be done. It simply says a prospective study about bullying at school and bullying at work. It doesn't provide information about the aim of the study or the study area. The references are provided. In text references have been provided. References seems relevant and authentic.

Introduction/Background This section has been presented in detail in different sub headings. It has described what bullying is and has considered bullying as a social and clinical problem. The prevalence, consequences and risk factors of bullying has been shown where various literature and evidences related to bullying has been presented. Literature have been searched and relevant evidences has been shown. The introduction/background section seems well presented. The aim and objectives of the study has also been presented.

Methods The process of subject selection has been explained. The data was collected from an ongoing study of a birth cohort study. But it is not clear on why this group was studied, i.e the rational for selecting this particular group. The variables have been well explained. Different variables like occurrence, severity and impact of manifold symptoms of physical and mental health problems, exposures at school and at home and information on parental socioeconomic status and social background of the participants were described. In addition, outcome measures of bullying, parental bonding, adolescent personal characteristics were also described. The study methods are valid as valid and reliable tools have been used. Sufficient information provided to replicate the study as the methodology has been explained in detail.

Results The data and tables are presented well. However some tables are too long (Table 4) and difficult to understand. The text explains the tables well and in detail. Various associations have been provided as well. The results are simple and easy to understand.

Discussions The results have been discussed in multiple angles. The findings have been supported by evidences and literature from other existing studies. The aim of the study and the findings have been explained. The limitations have also been explained as well as the future area and considerations for research.

Overall The study design was appropriate as it was a prospective study. It is a longitudinal study and data was collected from the same group twice with a gap of 3 years. The study identified the multiple risk factors on bullying both in school and work settings. This paper has not discussed on the intervention programmes to control or prevent bullying. The article is consistent in itself.

Overall Statement Bullying is a serious problem and it has serious consequences. This study is a prospective study about identifying risk factors for bullying. Data was collected at two points of time 2004 (baseline) and 2007 (endline). The age of the participants were 14-15 in 2004 and between 17-18 in 2007. Questionnaire was used to collect data, In 2004, 3054 individuals answered the question and 2181 individuals of the same cohort participated in both rounds. The study identified various risk factors for bullying. The strongest risk factor for being bullied was being bullied previously. Hence there is a need for early prevention of bullying in schools.

Strength The aims are clear. The sample size is fine. The methods are appropriate.

Weaknesses and Improvements: The title can be made specific. Some more information on the selection of the particular birth cohort and the sample population is required. The interventions/programs to prevent/reduce bullying has not been explained.