This cross-sectional comparative study was done among secondary school adolescents (urban and rural), aged 10 to 19 years in government owned schools within the chosen LGAs in Anambra State. The State has its capital and seat of government at Awka, with twenty-one LGAs and three senatorial zones namely Anambra South, Anambra Central and Anambra North.(20) The name Anambra was derived from the Omambala River (Anambra River) which is a tributary of the River Niger. The boundaries of Anambra State are formed by Delta State to the west, Imo State and Rivers State to the south, Enugu State to the east and Kogi State to the north. The major ethnic group of the State is Igbo (98% of the population), and a small population of Igala (2% of the population) living mainly in the north-western part of the State.(21) Other ethnic groups in Nigeria (from different tribes and culture) and even non-Nigerians, also live in the State as civil servants and for businesses. Christianity is the predominant religion, while others are Traditional African religion and Islam. Anambra State has 642 secondary schools, 257 of which are owned by the government (public secondary schools). The State has literacy rate of 70%.(21)
A minimum sample size of 942 was calculated to determine a difference in urban and rural in-school adolescents with anxiety disorders at 80% power and 95% confidence level. A total of 1187 in-school adolescents were studied at the end, adding more to the power of the study.
A multi-stage sampling technique was used in this study. At first stage, an urban and rural LGAs were selected from each senatorial zone by simple random sampling method (employing simple balloting). From Anambra North senatorial zone, Onitsha South LGA and Anambra-West LGA were the urban and rural LGAs respectively, while Awka South and Awka North were used as urban and rural LGAs respectively from Anambra Central senatorial zone. In the Anambra South senatorial zone, Nnewi North and Orumba North were selected as the urban and rural LGAs respectively. Proportionate allocation was employed in the second stage to select eighteen schools, taking cognizance of the varied number of schools in each LGA within the 3 senatorial zones. The third stage selection of classes, where both junior and senior secondary arms of the schools were considered for better spread. At the fourth stage, the participants were selected from the chosen class by employing systematic random sampling. From the school records, the population of the urban schools ranged from 600 to 2000, while that of the rural schools ranged from 300 to 600. The implication was that the number of participants needed from the rural schools ranged from 45 to 60, while that of the urban schools ranged from 60 to 90 participants. This gave the average expected number of participants per school as 50 for rural, and 70 for urban schools. This translated to average of 8 participants per class in the rural areas, and 12 participants per class in the urban areas. The sampling interval, k was calculated as appropriate, while the first participant with k was chosen using simple random sampling.
Study Instrument
The study instrument was an interviewer-administered pretested questionnaire adopted from General Anxiety Disorder (GAD-7), which is a brief self-report scale but with good reliability and validity.(22) The total score of 10 is used as diagnostic cut-off point for further evaluation.(22) Clinical evaluation was not included in this study to make definitive diagnosis of anxiety. GAD-7 of 10 and above has been supported for screening/diagnosis of Generalized anxiety. The scores obtained in GAD-7 ranges between 0 and 21, with scores of 5, 10, and 15 representing the cut-points for mild, moderate and severe anxiety respectively.(22) Increasing scores on the scale of GAD-7 were found to be strongly associated with multiple domains of functional impairment.(22)
Ethical Consideration
Prior to collection of data, permission was obtained from the Government of Anambra State Post Primary Schools Service Commission-Headquarters Awka, Principals of the respective schools and the Ethics Committee of Nnamdi Azikiwe University Teaching Hospital, Nnewi. Informed consent was obtained from each participant aged more than 18 years and assent from those less than 18 years, freely and without coercion after thorough explanation of the study. Informed permission was also sought from parents/guardians through the various school authorities. The participants were then guided to answer the questions in the study instrument to ensure quality data.
Data Management
Data analysis was done using the IBM Statistical Package for the Social Sciences (SPSS) version 26.(23) Anxiety was used as the dependent (outcome) variables in this study. The independent variables were location, age, gender, tribe, siblings, birth order, class, student type, family structure, living condition, and educational status participants' parents. For the purpose of this study, GAD-7 score ≥ 10 was set as cut-off points for diagnosis of anxiety. Chi-square test of association was done, using significance level of 5%. In order to test the independent association between the outcome variables and the covariates like age-category, birth order, family structure and ACE score, binary logistic regression was used. The magnitude of the associations between each variable and anxiety disorders, while holding other variables constant was quantified using odd ratios (ORs) at 95% confidence interval. Significance was computed at p < 0.05.