Tables
- TABLE 1
Participant characteristics
Category Total n=3979 Male 1731 (43.5) Ancestry Black African 1699 (42.7) Caucasian 463 (11.6) Mixed ancestry 1683 (42.3) Other 134 (3.4) School type Public 3771 (94.8) Private 208 (5.2) Highest level of maternal education Primary school 298 (7.5) Secondary 2002 (50.3) Tertiary 1597 (40.1) Not reported 82 (2.1) Previous tuberculosis treatment 279 (7.0) Outdoor pollution 1334 (33.5) Self-reported smoking (current) 348 (8.8) Maternal smoking 982 (24.7) Paternal smoking 1402 (35.2) Wood used for heating or cooking 288 (7.2) Exposure to pets 2711 (68.1) Mother or father employed 3523 (88.5) Home type – informal home 417 (10.5) Household assets (<7 items) 1975 (49.6) Body mass index kg·m−2 Less than 18.5 1105 (27.8) 18.5 to 24.99 2119 (53.2) Above 25 747 (18.8) Not reported 8 (0.2) - TABLE 2
Comparison of prevalence of asthma symptoms by written questionnaire among South African adolescents, 2002 (ISAAC III) and 2017 (GAN I)
2002 (ISAAC III) n (%) 2017 (GAN I) n (%) 2002 to 2017 OR (95% CI) Subjects n 5037 3979 Wheeze ever 1670 (33.1) 1373 (34.5) 1.06 (0.97–1.16) Wheezing last 12 months 1025 (20.3) 847 (21.3) 1.06 (0.96–1.17) Four or more attacks of wheezing in last 12 months 254 (5.0) 230 (5.8) 1.15 (0.96–1.39) Woken by wheezing one or more nights per week in last 12 months 252 (5.0) 275 (6.9) 1.41 (1.18–1.68) Severe wheeze limiting speech to one or two words at a time in last 12 months 395 (7.8) 468 (11.8) 1.57 (1.36–1.80) Exercise-induced wheeze in last 12 months 1641 (32.6) 1431 (36.0) 1.16 (1.06–1.27) Night cough in last 12 months 1846 (36.6) 1648 (41.4) 1.22 (1.12–1.33) Diagnosis of asthma ever 725 (14.4) 660 (16.6) 1.18 (1.05–1.33) - TABLE 3
Comparison of prevalence of asthma symptoms by video questionnaire among South African adolescents, 2002 (ISAAC III) and 2017 (GAN I)
Timeframe 2002 (ISAAC III) n (%) 2017 (GAN I) n (%) 2002 to 2017 OR (95% CI) Wheeze Ever 840 (16.9) 887 (22.5) 1.45 (1.30–1.61) In the last 12 months 559 (11.2) 737 (18.7) 1.84 (1.63–2.07) In the last month 351 (7.0) 513 (13.0) 1.92 (1.66–2.21) Exercise-induced wheeze Ever 1070 (21.3) 1480 (37.5) 2.23 (2.03–2.44) In the last 12 months 692 (13.9) 1205 (30.6) 2.76 (2.49–3.07) In the last month 466 (9.4) 890 (22.6) 2.86 (2.53–3.23) Nocturnal wheeze Ever 459 (9.2) 517 (13.1) 1.50 (1.32–1.72) In the last 12 months 265 (5.3) 376 (9.5) 1.90 (1.61–2.23) In the last month 194 (3.9) 275 (7.0) 1.87 (1.55–2.26) Nocturnal cough Ever 1501 (30.1) 1147 (29.1) 0.97 (0.88–1.06) In the last 12 months 957 (19.2) 863 (21.9) 1.19 (1.08–1.32) In the last month 620 (12.5) 618 (15.7) 1.32 (1.17–1.49) Severe wheeze Ever 603 (12.1) 583 (14.8) 1.28 (1.13–1.44) In the last 12 months 347 (7.0) 403 (10.2) 1.47 (1.27–1.71) In the last month 216 (4.3) 296 (7.5) 1.81 (1.51–2.17) - TABLE 4
Univariate and multivariate analysis of exposures and current self-reported asthma on the written questionnaire
Risk factor Current wheeze n=847 (%) No current wheeze n=3132 (%) Univariate analysis Multivariate analysis OR (95% CI) p-value OR (95% CI) p-value Sex (male) 327 (38.6) 1404 (44.8) 0.77 (0.66–0.90) 0.001 0.79 (0.67–0.93) 0.006 Private school 69 (8.1) 139 (4.4) 1.90 (1.40–2.60) <0.001 1.66 (1.20–2.30) 0.002 Outdoor pollution 303 (35.8) 1031 (32.9) 1.10 (1.00–1.30) 0.115 Self-reported smoking (current) 113 (13.3) 235 (7.5) 1.90 (1.49–2.41) <0.001 1.88 (1.46–2.410 <0.001 Maternal smoking 235 (27.7) 747 (23.9) 1.23 (1.03–1.46) 0.019 1.07 (0.88–1.29) 0.520 Paternal smoking 325 (38.4) 1077 (34.4) 1.18 (1.01–1.39) 0.036 1.13 (0.95–1.35) 0.168 Wood used for heating or cooking 76 (9.0) 212 (6.8) 1.36 (1.03–1.79) 0.029 1.18 (0.88–1.57) 0.271 Exposure to pets 633 (74.7) 2078 (66.3) 1.50 (1.26–1.78) <0.001 1.40 (1.16–1.67) <0.001 Mother or father employed 781 (92.2) 2742 (87.5) 1.57 (1.18–2.08) 0.002 1.48 (1.10–2.00) 0.011 Home type – informal 85 (10.0) 332 (10.6) 0.94 (0.73–1.21) 0.634 Household assets (<7 items) 369 (43.6) 1606 (51.3) 1.36 (1.17–1.59) <0.001 0.86 (0.73–1.01) 0.078 Body mass index above 25 kg·m−2 171 (20.2) 576 (18.4) 1.12 (0.93–1.36) 0.240 - TABLE 5
Univariate and multivariate analysis of exposures and severe asthma on the written questionnaire
Risk factor Severe wheeze n=669 (%) No severe wheeze n=3310 (%) Univariate analysis Multivariate analysis OR (95% CI) p-value OR (95% CI) p-value Sex (male) 287 (42.9) 1444 (43.6) 0.97 (0.82–1.15) 0.730 Private school 29 (4.3) 179 (5.4) 0.79 (0.53–1.18) 0.256 Outdoor pollution 260 (38.9) 1074 (32.4) 1.33 (1.12–1.59) 0.001 1.26 (1.06–1.51) 0.010 Self-reported smoking (current) 103 (15.4) 245 (7.4) 2.28 (1.78–2.92) <0.001 2.29 (1.78–2.94) <0.001 Maternal smoking 146 (21.8) 836 (25.3) 0.84 (0.68–1.02) 0.079 Paternal smoking 240 (35.9) 1162 (35.1) 1.01 (0.88–1.53) 0.612 Wood used for heating or cooking 49 (7.3) 239 (7.2) 1.02 (0.74–1.40) 0.925 Exposure to pets 483 (72.2) 2228 (67.3) 1.26 (1.05–1.52) 0.014 1.32 (1.09–1.61) 0.005 Mother or father employed 590 (88.2) 2933 (88.6) 0.89 (0.68–1.17) 0.409 Home type – informal 90 (13.5) 327 (9.9) 1.42 (1.10–1.82) 0.006 1.38 (1.05–1.81) 0.019 Household assets (<7 items) 363 (54.3) 1612 (48.7) 1.25 (1.06–1.48) 0.009 1.18 (0.99–1.42) 0.072 Body mass index above 25 kg·m−2 130 (19.4) 617 (18.6) 1.05 (0.85–1.30) 0.638
Vol 7 Issue 2
Table of Contents
Asthma in South African adolescents: a time trend and risk factor analysis over two decades
