Ethnic Disparity in the Incidence of Scoliosis Among Adolescents in Tianzhu Tibetan Autonomous County, China

Abstract

Objectives: To determine the influence of ethnic disparities, socioeconomic status (SES) and hukou on the incidence of scoliosis.

Methods: We enrolled 2,445 junior high school students (Han: 1,153; ethnic minorities: 1,292) aged 12-16 years from two schools in Tianzhu Tibetan Autonomous County, Gansu Province from November 2020 to February 2021. We measured the angle of trunk rotation (ATR) using a scoliometer. Two-factor analysis of variance was used to comparatively analyze differences in the ATR according to ethnicity, age, sex, body mass index (BMI), and SES between the groups. Associations between risk factors and scoliosis were estimated using odds ratios and 95% confidence intervals with an unconditional multivariate logistic regression model for the two groups.

Results: Adolescents with Han ethnicity were more likely to have scoliosis than their ethnic minority counterparts (10.8% vs. 7.1%, P < 0.05). The ATR value in the Han group decreased with age whereas the minority group showed an upward trend (P < 0.05). The difference between ethnic groups was not significant, only at level 3. In particular, the ATR values among Han girls were significantly higher than those of ethnic minority girls (P < 0.05). Compared with Han adolescents, the BMI of ethnic minorities had a greater impact on the ATR. A statistically significant difference in SES was found between the two ethnic groups (P < 0.05). Hukou and parents' occupation had an important influence on the onset of scoliosis.

Conclusions: Han adolescents had higher ATR values and were more likely to have scoliosis than ethnic minority adolescents in our study. Growth and development indicators (height and BMI) and differences in SES between the two groups played an important role.

Keywords: ethnic disparity; hukou; risk factors; scoliosis; socioeconomic status.

Figure 1

Two-factor analysis of variance to assess differences in ATR values by ethnicity and age. (A) Level 1, proximal thoracic (T1–T4); (B) level 2, main thoracic (T5–T12); (C) level 3, lumbar (T12–L4); (D) Max, maximum value among the three levels.

Figure 2

Two-factor analysis of variance to assess differences in ATR values by ethnicity and sex. (A) Level 1, proximal thoracic (T1–T4); (B) level 2, main thoracic (T5–T12); (C) level 3, lumbar (T12–L4); (D) Max, maximum value among the three levels.

Figure 3

Scatter plot with trend line according to BMI and ATR between Han and ethnic minority groups. (A) Level 1, proximal thoracic (T1–T4); (B) level 2, main thoracic (T5–T12); (C) level 3, lumbar (T12–L4); (D) Max, maximum value among the three levels. (a) Han, (b) minority, (c) total. BMI, body mass index; ATR, angle of trunk rotation.

Figure 4

Two-factor analysis of variance to assess differences in ATR value by ethnicity and SES-related factors: (A) education level; (B) household income; (C) occupation; and (D) hukou. (A) Level 1, proximal thoracic (T1–T4); (B) level 2, main thoracic (T5–T12); (C) level 3, lumbar (T12–L4); (D) Max, maximum value among the three levels.

Figure 5

Forest map comparing differences in the influence of various factors on scoliosis between the two groups. Bold font indicates statistically significant variables. Sex, age, height, BMI, and SES-related factors were independent variables, and ATR value ≥ 5° was the dependent variable in the logistics regression model of (A) Han and (B) ethnic minority groups. BMI, body mass index; SES, socioeconomic status; ATR, angle of trunk rotation; CI, confidence interval.