The present pre-post intervention study without external controls was conducted on 1944 students aged 14-20 years and studying in classes 9 to 12, from 30 schools from both rural and urban areas of Ujjain district located in MP. The population of the district is approximately 1.9 million, with 61% of the population resides in rural areas having agricultural economy [8]. Children under 15 years of age constitute 28.9% of the total population [9].

A total of 50 students were enrolled in a pilot study to calculate sample size as there are no similar Indian studies. Of the total questions, administered to the participants, 48–56% were answered correctly. To maximize the sample size, the lower proportion 48% of the range was used. Assuming a two-sided alpha error of 0.05, margin of error of 0.04, and power of 90%, the sample size was 1640. An additional 10% was added to the above sample size to compensate for attrition or refusal, resulting in the final sample size of 1804.

The institutional ethics committee of RD Gardi Medical College, Ujjain approved the research protocol. Prior permission was taken from the District Education Officer and the District Magistrate. Invitations were sent to the principals or heads of the selected schools, who reviewed the study design and approved participation in the study. Informed written assent consent to participate in the study was obtained from students and their parents.

A two-stage (schools and classrooms) cluster sampling was used. Out of the total of 514 higher secondary schools in Ujjain, 93 schools had 40-50 students in class 9-12. We selected 30 schools using random numbers. During second stage sampling, we randomly selected 2002 students of class 9-12 from these schools. Of these, parents of 1944 children provided consent, and were enrolled for the study.

Data were collected for six months, duration from July, 2018 to December, 2018. A structured questionnaire was developed in English and was then translated to Hindi as per World Health Organization recommendations. Forward translation was performed by a bilingual professional health care worker, namely a pediatrician who had injury work experience, and an expert panel resolved any discrepancies in translation [10]. The questionnaire was back translated to English to ensure that the original meaning had been retained. Pilot testing of the questionnaire was performed on 10 school students (aged 15-18 years), and the final version was then produced.

A team of trained research assistants asked the students to fill-in a questionnaire following which the educational intervention was administered. Post-training assessment of students was conducted one-month later using the same structured questionnaire. Students took approximately 20 min to complete the questionnaire. The questionnaire consisted of 25 questions, of which 8 were on prevention and 17 were on first aid. A score of 1 was given to each correct answer and the minimum and the maximum score obtained was 0 and 25, respectively.

Educational intervention: A visit to each school was scheduled before starting the educational intervention. The training session used a training module based on the Red Cross Society first aid module [11]. The length of an intervention session was 40 min. A total of 120 sessions were conducted in 6 months which included 60 pre-intervention and equal number of post-intervention sessions. Apart from post-intervention sessions no other reinforcement was provided to the students. A minimum gap of one month was maintained between pre- and post-intervention sessions.

The educational intervention included lectures on different types of unintentional injuries, such as burns, poisoning, drowning, suffocation, and physical injuries (wounds, fractures, and road traffic accidents) and their first aid through PowerPoint presentations, pictures, and videos. Other lecture topics in the training included basic information on the ‘Good Samaritan law’ in India, importance of the golden hour, and importance and components of the first aid box. Participants were not informed in the beginning that they would be tested later.

Fidelity of the intervention: The intervention design was informed by the theoretical framework of the infor-mation-motivation-behavioural skills (IMB) model of health behavior [12]. Further, the research assistants were trained by the principal investigator to maintain the fidelity of the intervention. The intervention module consisted of a 3-hour training session involving a discussion on all pictures, videos, and each slide in the power point presentation regarding the content and the way of delivering the lecture. The concepts were reinforced by providing the research assistants an opportunity to engage in role-playing. The session was repeated once every fortnight during the study period. To ensure the implementation of the intervention, a training manual was used to articulate the contents and delivery of the educational interventions. The participants’ receipts of intervention were assessed on the basis of their atten-dance and the acquired knowledge post-intervention.

The main outcome variable (dependent variable) was the change in pre- and post-intervention knowledge score. Age, gender, school location, school type, medium of education in the schools, and the class in which the students were studying were the main independent variables.

Of the 1944 students, 1105 (57%) were boys and the remaining 839 (43%) were girls. The mean (SD) age of the participating students in the study was 15.99 (1.33) years. Table I illustrates the demographic characteristics of the study participants.

The study findings demonstrated that the school-based educational intervention significantly increased the knowledge on the prevention of unintentional injuries and first aid among adolescents, with a large effect size. The present study adds to the body of evidence generated by a systematic review on the effectiveness of a school-based educational intervention aimed at increasing the know-ledge of adolescents on unintentional injury prevention and first aid [8]. Although knowledge of students improved, but this knowledge does not necessarily lead to motivational and behavioral changes [13]. The present study worked on the health promotion information side only.

The results of our study are consistent with previous first aid educational intervention studies on adolescents [14]. A study conducted in Australia also reported that the burn victims receive inadequate first aid due to inadequate knowledge of the recommended 10-20 minutes time for submerging the burned part in water [15].

In our study, the cardiopulmonary resuscitation (CPR) knowledge of students significantly increased following educational intervention. The finding is consistent with studies conducted in New Zealand and Australia [15,16]. The Australian study also revealed that a training program on first aid, CPR, and beach safety offered to school students enhanced their confidence level in providing first aid following drowning [16]. India instituted the ‘Good Samaritan law’ to support bystanders for helping trauma victims in 2016 [17], and therefore, students were also educated about the law.

In the present study, younger students outperformed the older ones. The finding is consistent with a study on first aid training of preschool children in Egypt, which reported that age is directly associated with the first aid knowledge of students [18]. However, another review from Australia suggests that first aid learning, and retention of knowledge and skills generally increase with age and practical training sessions [19].

In the present study, boys outperformed girls. The finding is contrary to a study in Saudi Arabia conducted on university students, which reported that females’ knowledge on CPR and trauma management was superior to those of male students [20]. Moreover, the performance of urban school students was found superior to their rural counterparts in the present study. Another first aid educational intervention study on the knowledge assessment of adolescents also reported that the residence significantly affected the knowledge scores [21]. Further-more, students of public schools outperformed those of private schools in our study. However, a study conducted in Ethiopia reported that government school teachers possess less knowledge and lack appropriate attitude on first aid compared with private school teachers [22]. In the present study, students of Hindi medium schools outperformed those of English medium schools. This might be due to the fact that students learn better when taught in their mother tongue [23].

The research team conducting educational intervention was same in all schools. Random selection of participants and a robust statistical analysis and multi-variate quantile regression are also the other merits of our study. However, lack of external controls, poses a threat to generalizability of the results. Pre-post design using the same questionnaire might have allowed some students to memorize the questions (interaction effect). However, the students were not aware that a post-test would be done. The study design allowed the interpretation of results based on a temporal relationship of measurements with the educational intervention. Additionally, the study was not designed to follow-up students for the evaluation of long-term knowledge retention. We do not currently know the number of reinforcement sessions needed for long term knowledge retention among adolescent students, which needs to be studied in future studies.

We conclude that educational interventions in school curriculums can strengthen the knowledge of adolescents on unintentional injury prevention and first aid. Quality school-based educational trainings can help raise aware-ness among adolescents.

Note: Supplementary material related to this study is available with the online version at www.indianpediatrics.net

Ethics clearance: Institutional Ethics Committee, RD Gardi Medical College, Ujjain; IEC-RDGMC 354, January 08, 2014.

Contributors: SM, AM, JJ, AP: contributed towards the conception and design of the work, analysis and interpretation of data for the work, drafting the work or revising it critically for important intellectual content, and final approval of the version to be published. All authors agreed to be accountable for all aspects of the work

Funding: Indian Council of Medical Research, New Delhi.

Competing interests: None stated.