Table 1 Characteristics of participants according to the different phases of CASPIAN studies
Demographic information | CASPIAN-III (2009–2010) | CASPIAN-IV (2011–2012) | CASPIAN-V (2014–2015) | P-value |
|---|---|---|---|---|
Age | ||||
 7–10 years | (−) | 4349 (32.2) | 4843 (33.9) | < 0.001* |
 11–14 years | 2593 (46.1) | 4678 (34.7) | 5591 (39.2) | |
 15–18 years | 3032 (53.9) | 4459 (33.1) | 3840 (26.9) | |
Gender | ||||
 Boy | 2801 (49.8) | 6846 (50.8) | 7228 (50.6) | 0.45 |
 Girl | 2824 (50.2) | 6640 (49.2) | 7046 (49.4) | |
Place of residence | ||||
 Urban | 3785 (69.3) | 10,191 (75.6) | 10,194 (71.4) | < 0.001 |
 Rural | 1677 (30.7) | 3295 (24.4) | 4080 (28.6) | |
Father’s occupation | ||||
 Unemployed | 342 (6.4) | 657 (5.0) | 860 (6.2) | < 0.001 |
 Worker/Employee | 3077 (57.2) | 7309 (56.1) | 8110 (58.8) | |
 Self-employed | 1961 (36.4) | 5062 (38.9) | 4833 (35.0) | |
Mother’s occupation | ||||
 Housewife | 5002 (91.0) | 11,883 (89.0) | 12,354 (87.2) | < 0.001 |
 Worker/Employee | 386 (7.0) | 1060 (7.9) | 1300 (9.2) | |
 Other | 110 (2.0) | 409 (3.1) | 514 (3.6) | |
Father’s education | ||||
 Illiterate | 807 (14.8) | 1471 (11.2) | 1734 (12.6) | < 0.001 |
 High school diploma or lower | 4125 (75.7) | 9788 (74.8) | 10,163 (73.7) | |
 Bachelor degree or higher | 520 (9.5) | 1831 (14.0) | 1893 (13.7) | |
Mother’s education | ||||
 Illiterate | 1263 (22.9) | 2270 (17.0) | 2500 (17.6) | < 0.001 |
 High school diploma or lower | 3973 (72.2) | 9925 (74.3) | 10,148 (71.6) | |
 Bachelor degree or higher | 269 (4.9) | 1167 (8.7) | 1524 (10.8) | |
Family members | ||||
 4 or less | 1953 (39.4) | 6491 (48.9) | 6742 (47.9) | < 0.001 |
 5 and more | 3008 (60.6) | 6778 (51.1) | 7336 (52.1) | |
Life satisfaction | ||||
 Satisfied | 3135 (56.9) | 10,698 (79.9) | 11,216 (78.9) | < 0.001 |
 Dissatisfied | 2379 (43.1) | 2689 (20.1) | 2996 (21.1) | |
Socio-economic status of family | ||||
 Weak | 1052 (19.8) | 4147 (33.5) | 4562 (33.5) | < 0.001 |
 Moderate | 2085 (39.2) | 4100 (33.1) | 4521 (33.2) | |
 Good | 2178 (41.0) | 4143 (33.4) | 4555 (33.4) | |
Socio-economic status of place of residence | ||||
 South east | 557 (9.9) | 1181 (8.8) | 1919 (13.4) | < 0.001 |
 North & north east | 1073 (19.1) | 2359 (17.5) | 2398 (16.8) | |
 West | 2340 (41.6) | 6119 (45.4) | 6597 (46.2) | |
 Central | 1654 (29.4) | 3827 (28.4) | 3360 (23.5) | |
Physical activity | ||||
 Light | 2293 (41.5) | 4553 (34.1) | 4454 (33.4) | < 0.001 |
 Moderate | 1818 (32.9) | 4910 (36.8) | 4424 (33.2) | |
 Intense | 1417 (25.6) | 3886 (29.1) | 4440 (33.3) | |
ST | ||||
 2 h or less | 3475 (68.0) | 10,899 (81.4) | 12,135 (87.4) | < 0.001 |
 More than 2 h | 1634 (32.0) | 2494 (18.6) | 1752 (12.6) | |
Passive smoking | ||||
 Yes | 2002 (35.6) | 5802 (43.9) | 5772 (43.2) | < 0.001 |
 No | 3623 (64.4) | 7424 (56.1) | 7575 (56.8) | |