Objective To investigate the incidence rate, surgical rate and spontaneous cure of indirect inguinal hernia in children of Xinjiang region.

Methods Children, aged from 4‒14 years, coming from 24 kindergartens, 18 primary schools and 9 junior middle schools of 3 countries and 5 cities in Xinjiang Uygur Autonomous Region were recruited to participate as respondents. The survey time for baseline data collection was from May 2013 to June 2014 and the retrospective cross-sectional survey was conducted. Parents of children were investigated by questionnaire, and children were examined on site. Observation indicators: (1) results of questionnaire survey; (2) illness and treatment of children involved in the study; (3) follow-up. Follow-up was conducted using telephone interview. Children who had been diagnosed and not been treated surgically at the time of questionnaire survey were followed up to detect disease progression and treatment in the past 5 years. If the symptoms of a child had disappeared during follow-up, parents of the child should accompany the child to hospital for physical examination and B-ultrasound examination to confirm the diagnosis, and then follow-up was conducted by telephone interview. The follow-up was up to January 2020. Count data were described as absolute numbers and percentages, and compari-son between groups was conducted using the chi-square test. Odds ratio and 95% confidence interval were calculated.

Results (1) Results of questionnaire survey. A total of 19 132 question-naires were distributed, and 19 132 complete questionnaires were recovered. Of the 19 132 children who completed the questionnaire survey, there were 9 670 males and 9 462 females. (2) Illness and treatment of children involved in the study. ① Incidence of indirect inguinal hernia in children with different sexes. Of the 19 132 children, 498 cases were diagnosed as indirect inguinal hernia, including 368 boys and 130 girls, with the prevalence as 3.806%(368/9 670) and 1.374%(130/9 462), respectively. There was a significant difference in the prevalence of indirect inguinal hernia between boys and girls (χ²=111.54, P<0.05). The proportion of boys and girls in children with indirect inguinal hernia was 73.896%(368/498) and 26.104%(130/498), respectively, with the ratio of 2.8:1. The prevalence of boys was higher than girls (odds ratio=2.84, 95% confidence interval as 2.32‒3.48).② Age of children at first onset. Of the 498 children with indirect inguinal hernia, 59 cases were aged 1‒4 years at first onset including 54 boys and 5 girls, 264 cases were aged 5‒8 years including 196 boys and 68 girls, 148 cases were aged 9‒12 years including 104 boys and 44 girls, 27 cases were aged 13‒14 years including 14 boys and 13 girls. There was a significant difference in the age of children at first onset between boys and girls (χ²=17.33, P<0.05). ③ Pathogenic factors in children with indirect inguinal hernia. Of the 498 children with indirect inguinal hernia, 457 cases had complete family history and crying history, and 41 cases were missing. Family history: of the 457 children with indirect inguinal hernia who had complete family history, there were 175 cases with the family history of indirect inguinal hernia and 282 cases without the family history. Of the 478 healthy children surveyed in the same period, there were 25 cases with the family history and 453 cases without the family history. There was a significant difference in the family history between the 457 children with indirect inguinal hernia and the 478 healthy children (χ²=515.89, P<0.05). Crying history: of the 457 children with indirect inguinal hernia who had complete crying history, there were 194 cases with obvious crying history and 263 cases without obvious crying history. Of the 496 healthy children surveyed in the same period, there were 99 cases with obvious crying history and 397 cases without obvious crying history. There was a significant difference in the crying history between the 457 children with indirect inguinal hernia and the 496 healthy children (χ²=56.51, P<0.05). ④ Surgical treatment. Of the 498 children with indirect inguinal hernia, 233 cases underwent surgical treatment including 217 boys and 16 girls, 265 cases were followed up without surgical treatment including 151 boys and 114 girls. The surgical rate for indirect inguinal hernia in boys and girls was 58.967%(217/368) and 12.308%(16/130), respectively, showing a significant difference between them (χ²=84.01, P<0.05). The operation ratio of boys and girls was 13.6:1, and the surgical rate of boys was higher than girls (odds ratio=10.24, 95% confidence interval as 5.83‒17.98). (3) Follow-up. All the 265 children without surgical treatment for indirect inguinal hernia were followed up for 5 years. During the follow-up, there were 142 of 151 boys with surgical treatment and 9 boys without surgical treatments, showing negative in spontaneous cure. There were 27 of 114 girls with surgical treatment and 87 girls without surgical treatment, showing 55 cases positive in spontaneous cure and 32 cases still with indirect inguinal hernia. There was a significant difference in spontaneous cure between the 151 boys and the 114 girls (χ²=143.79, P<0.05).

Conclusion In Xinjiang region, the incidence rate and surgical rate of indirect inguinal hernia are lower in girls compared with boys, and the spontaneous cure rate is higher in girls compared with boys.