Patient characteristics
Total of 285 574 patients attended to the respiratory outpatient department of the hospital during the 10-year study period. Preschool children aged < 7 years old accounted for 88.0% of all the children. The number of children aged 1 to < 4 years was twice of those aged < 1 years and 4 to < 7 years. Males accounted for 59.6% of the patient population, 39.4% of the patients were covered by government insurance and 60.6% were self-finance. Respiratory specialist clinic provided medical service for 46.5% patients mainly with special respiratory diseases. The doctors with associate professor position or above provided medical service for 52.3% patients in the expert-clinic. The median and the 25th and the 75th percentiles of visits per children were 1 and (1, 3), and the number of visits had no significant difference between the patients covered by government insurance and those who were self-finance [1(1, 3) vs. 1(1, 2)]. (Table 1)
Table 1
Characteristics of patients, 2009–2018
| Patients visited the respiratory outpatient department |
n of patients | 285574 |
Age, n(%) | |
<1 year | 74034(23.0) |
1 to < 4 years | 132178(41.1) |
4 to < 7 years | 76818(23.9) |
7 to < 12 years | 33825(10.5) |
12 to < 18 years | 4512(1.4) |
Total [1] | 321368 |
Sex, n(%) | |
Male | 170192(59.6) |
Female | 115382(40.4) |
Payer type, n(%) | |
Government insurance | 112495(39.4) |
Self-finance | 173079(60.6) |
Clinic types, n(%) | |
Specialist Clinic | 170808(46.5) |
Expert-clinic | 192081(52.3) |
Disease-specific Clinic | 4434(1.2) |
Total [2] | 367323 |
Average visits per patients | |
Government insurance | |
Mean ± SD | 2.9 ± 4.0 |
Median(P25,P75) | 1(1,3) |
Self-pay | |
Mean ± SD | 2.1 ± 2.7 |
Median(P25,P75) | 1(1,2) |
Total | |
Mean ± SD | 2.4 ± 3.3 |
Median(P25,P75) | 1(1,3) |
Note: [1] A child could contribute data to multiple age groups as he or she visited the department of respiratory disease in different year. |
[2] A child could contribute data to multiple clinic types as he or she visited the department of respiratory disease in different type. |
Overall trend in ROVs
During the 10-year study period, the overall ROVs were 698 054 with an average AGR of 15.2%. The AGR stayed stable around 10% after 2013. (Fig. 2)
Age trends in ROVs
Figure 3 displays the change of the proportions and trends in number of visits at different age groups through the years. For children aged < 1 year, the proportion of total visits declined from 24.3% in 2013 to 17.4% in 2018 (P < 0.001) and the annual visits increased over time with an average AGR of 14.7% (P < 0.001). For children aged 1 to < 4 years, they remained stable 43% of total visits and increased with an average AGR of 14.9%. For children aged 4 to < 7 years, the proportion of total visits increased from 22.8–28.4% (P < 0.001) and the average AGR appeared the highest of 16.9% among all age groups (P < 0.001). For children aged 7 to < 12 years and 12 to < 18 years, they accounted for 9% and 1% of total visits and the average AGR increased slowly from 13.1–13.8%, respectively.
Gender trends in ROVs
For male children, they accounted for 60.6% of total visits, from 62.9% in 2009 to 59.2% in 2018, with an average AGR of 14.4%. For female children, the proportion to total visits varied from 37.1% in 2009 to 40.8% in 2018 with an average AGR of 16.4%.
Overall diagnoses distribution
During the past 10 years, 23 different diagnoses categories were identified for all ROVs. Bronchitis was the most commonly identified diagnosis with 190 088 (27.6%) of total visits, followed by pneumonia (126 887, 18.5%), pneumonia affecting other systems (126 469, 18.4%), asthma and status asthmaticus (73 443, 10.7%), vasomotor and allergic rhinitis (62 951, 9.2%), other lower respiratory infections (42 353, 6.2%), and other respiratory diseases (65261, 9.4%). The distributions of all the identified diagnoses are shown in Fig. 4.
Gender- and age-specific trends in proportion of diagnoses
Figure 5 shows the change of proportions of the selected three main diagnoses, bronchitis, pneumonia, asthma and status asthmaticus, stratified by gender.
For male children, the proportion of bronchitis in all ages declined from 34.8% in 2009 to 25.6% in 2018. In different age categories, the proportion of bronchitis for children aged < 1 year declined from 34.5–24.8%, aged 1 to < 4 years 37.1–27.9%, aged 4 to < 7 years 34.5–25.7%, aged 7 to < 12 years 33.4–19.5%, and aged 12 to < 18 years 26.1–11.3%. For female children, the proportion of bronchitis in all ages and age-specific categories showed the similar decline through the years.
For male children diagnosed pneumonia, the proportion of the disease in all ages increased from 13.0% in 2009 to 21.7% in 2018. Comparing the different age categories, children aged < 1 year and 1 to < 4 years accounted for larger proportion of pneumonia (13.6% and 11.96% in 2009; and 22.1% and 22.4% in 2018) than the older age categories, for example, male children aged 4 to < 7 years, 7 < 12 years, and 12 to < 18 years (4.8%, 8.8%, and 7.4% in 2009; and 12.9%, 13.2%, and 12.7% in 2018). For female children, the proportion of pneumonia showed the similar increasing trend through the years.
For male children diagnosed asthma and status asthmaticus, the age differential phenomena were evident. Through the past 10 years, the proportion of asthma increased by age categories. Male children aged < 1 year and 1 to < 4 years had lower proportion (15.9% and 12.9% in 2009; and 12.1% and 8.2% in 2018, respectively) compared to the other age categories: aged 4 to < 7 years (20.4% in 2009; 17.3% in 2018), age 7 to < 12 years (24.9% in 2009; 22.7% in 2018), and aged 12 to < 18 years (35.1% in 2009; 28.6% in 2018). For female children, the proportion of asthma was lower than the male children at every age categories with similar change through the years. For example, 17.4% female children aged 7 to < 12 years were diagnosed asthma in 2009 and 13.6% in 2018, which were lower than those of the male children in the same age category (24.9% in 2009; 22.7% in 2018, respectively, P < 0.001).
Gender- and age-specific trends in visits of diagnoses
Table 2 showed the trends of the number of visits by respiratory diagnoses. For children diagnosed with bronchitis, the females had higher average AGR compared to the males in all age categories (14.6% vs. 10.39 for aged < 1y, 12.9% vs. 10.8% for aged 1 to < 4 years, 15.5% vs. 12.4% for aged 4 to < 7 years, 7.4% vs. 6.0% for aged 7 to < 12 years, and 6.8% vs. 2.5% for aged 12 to < 18 year). Children aged < 7 years have higher average AGR than the older children for both the males and females (P for trend < 0.001).
Table 2
Age- and gender-specific trends in average AGR of visits by diagnosis, 2009–2018
| < 1y | | 1y ~ | | 4y ~ | | 7y ~ | | 12 ~ < 18y |
| Average AGR (%) | P for trend | | Average AGR (%) | P for trend | | Average AGR (%) | P for trend | | Average AGR (%) | P for trend | | Average AGR (%) | P for trend |
Bronchitis |
Male | 10.39 | 0.004 | | 10.77 | 0.003 | | 12.38 | < 0.001 | | 6.01 | 0.008 | | 2.51 | 0.105 |
Female | 14.62 | < 0.001 | | 12.90 | 0.001 | | 15.49 | < 0.001 | | 7.37 | 0.002 | | 6.75 | 0.066 |
Pneumonia |
Male | 20.84 | < 0.001 | | 22.62 | < 0.001 | | 21.25 | < 0.001 | | 17.61 | < 0.001 | | 19.58 | < 0.001 |
Female | 23.98 | < 0.001 | | 22.30 | < 0.001 | | 23.17 | < 0.001 | | 21.06 | < 0.001 | | 27.03 | < 0.001 |
Asthma and status asthmaticus |
Male | 11.10 | 0.001 | | 8.79 | 0.038 | | 13.99 | 0.002 | | 11.37 | 0.001 | | 9.95 | 0.001 |
Female | 12.12 | < 0.001 | | 10.11 | 0.009 | | 18.06 | 0.001 | | 11.24 | < 0.001 | | 18.43 | 0.001 |
For children diagnosed with pneumonia, they had nearly two fold average AGR compared to the children diagnosed with bronchitis and asthma. Female children had also higher average AGR than the males in all age categories, and the average AGR varied little between different age categories.
For children diagnosed with asthma and status asthmaticus, the average AGR was similar to that of the children with bronchitis, while it was higher than that of children with bronchitis aged > = 7 years. For each age category, female children with asthma had higher average AGR compared to the male children (Ps <0.001).