Background
Methods
Data source and study sample
Empirical model and statistical analysis
Variables | Age group | |||
---|---|---|---|---|
0-9 years | 10-19 years | |||
controls | cases | controls | cases | |
Total number of observations | 665,588 | 26,178 | 683,315 | 27,500 |
Total number of individuals | 90,791 | 3,597 | 98,163 | 3,889 |
Male | 342,157 (51.41%) | 15,684 (59.91%) | 351,112 (51.38%) | 16,756 (60.93%) |
Age (years) | 4.54 (2.86) | 4.59 (2.85) | 14.54 (2.88) | 14.53 (2.87) |
Hospitalized at least once | 57,287 (8.61%) | 6,949 (26.55%) | 38,312 (5.61%) | 4,475 (16.27%) |
Days hospitalized (among those with at least one hospitalization) | 5.23 (11.34) | 8.08 (11.11) | 4.67 (9.60) | 5.64 (6.33) |
Maternal age (years) | 32.80 (5.38) | 32.74 (5.51) | 41.39 (5.42) | 41.27 (5.51) |
Paternal age (years) | 35.54 (6.17) | 35.59 (6.27) | 44.20 (6.11) | 44.17(6.27) |
Maternal income (DKK) | 146,463 (90,890) | 142,991 (84,593) | 149,570 (101,353) | 148,123 (113,759) |
Paternal income (DKK) | 242,329 (189,762) | 233,934 (171,085) | 259,505 (224,802) | 248,957 (205,933) |
Maternal education | ||||
Primary and lower secondary | 221,224 (33.24%) | 9,928 (37.92%) | 277,152 (40.56%) | 12,247 (44.53%) |
Upper and post-secondary | 267,481 (40.19%) | 9,957 (38.04%) | 250,418 (36.65%) | 9,656 (35.11%) |
Tertiary | 176,883 (26.58%) | 6,293 (24.04%) | 155,745 (22.79%) | 5,597 (20.35%) |
Paternal education | ||||
Primary and lower secondary | 175,444 (26.36%) | 7,808 (29.83%) | 210,665 (30.83%) | 9,604 (34.92%) |
Upper and post-secondary | 323,376 (48.59%) | 12,503 (47.76%) | 317,229 (46.43%) | 12,307 (44.75%) |
Tertiary | 166,768 (25.06%) | 5,867 (22.41%) | 155,421 (22.75%) | 5,589 (20.32%) |
Maternal occupational status | ||||
Self-employed | 26,960 (4.05%) | 943 (3.60%) | 50,088 (7.33%) | 1,873 (6.81%) |
Employed | 480,752 (72.23%) | 18,666 (71.30%) | 509,599 (74.58%) | 20,000 (72.73%) |
Unemployed/others | 157,876 (23.72%) | 6,569 (25.09%) | 123,628 (18.09%) | 5,627 (20.46%) |
Paternal occupational status | ||||
Self-employed | 65,939 (9.91%) | 2,715 (10.37%) | 97,360 (14.25%) | 3,955 (14.38%) |
Employed | 531,849 (79.91%) | 20,552 (78.51%) | 519,868 (76.08%) | 20,328 (73.92%) |
Unemployed/others | 67,800 (10.19%) | 2,911 (11.12%) | 66,087 (9.67%) | 3,217 (11.70%) |
Maternal marital status | ||||
Married | 449,196 (67.49%) | 17,113 (65.37%) | 531,119 (77.73%) | 20,912 (76.04%) |
Cohabiting | 139,977 (21.03%) | 5,700 (21.77%) | 54,594 (7.99%) | 2,213 (8.05%) |
Single | 76,415 (11.48%) | 3,365 (12.85%) | 97,602 (14.28%) | 4,375 (15.91%) |
Maternal urbanization | ||||
> = 1000 Inh/km2 | 107,350 (16.13%) | 3,877 (14.81%) | 90,742 (13.28%) | 3,948 (14.36%) |
500-999 Inh/km2 | 103,838 (15.60%) | 4,237 (16.19%) | 103,881 (15.20%) | 4,227 (15.37%) |
200-499 Inh/km2 | 126,009 (18.93%) | 4,840 (18.49%) | 130,914 (19.16%) | 4,817 (17.52%) |
100-199 Inh/km2 | 96,566 (14.51%) | 3,651 (13.95%) | 104,857 (15.35%) | 4,323 (15.72%) |
50-99 Inh/km2 | 143,713 (21.59%) | 5,719 (21.85%) | 156,472 (22.90%) | 6,058 (22.03%) |
< 50 Inh/km2 | 88,112 (13.24%) | 3,854 (14.72%) | 96,449 (14.11%) | 4,127 (15.01%) |
Exposure time (days living in Denmark per year) | 347.50 (62.19) | 348.12 (61.87) | 364.67 (10.52) | 364.83 (9.58) |
Variables | Age group | |||||||||
---|---|---|---|---|---|---|---|---|---|---|
20-29 years | 30-39 years | 40-49 years | 50-59 years | 60-68 years | ||||||
controls | cases | controls | Cases | controls | cases | controls | cases | controls | cases | |
Number of observations | 809,974 | 30,665 | 843,807 | 28,199 | 776,786 | 22,259 | 461,190 | 11,978 | 114,708 | 2,594 |
Male | 414,779 (51.21%) | 18,839 (61.43%) | 430,615 (51.03%) | 17,207 (61.02%) | 394,148 (50.74%) | 13,088 (58.80%) | 231,696 (50.24%) | 6,902 (57.62%) | 56,652 (49.39%) | 1,489 (57.41%) |
Age (years) | 24.56 (2.87) | 24.49 (2.86) | 34.53 (2.87) | 34.42 (2.87) | 44.29 (2.84) | 44.17 (2.84) | 53.84 (2.79) | 53.79 (2.78) | 62.52 (2.17) | 62.35 (2.09) |
Exposure time (days) | 363.56 (19.43) | 363.65 (18.96) | 364.24 (15.50) | 364.29 (15.35) | 364.40 (14.31) | 364.25 (15.72) | 363.94 (17.97) | 363.78 (18.44) | 363.01 (23.85) | 362.03 (29.29) |
Hospitalized at least once | 94,494 (11.67%) | 4,299 (14.02%) | 93,509 (11.08%) | 3,331 (11.81%) | 65,961 (8.49%) | 2,194 (9.86%) | 45,083 (9.78%) | 1,327 (11.08%) | 14,784 (12.89%) | 346 (13.34%) |
Days hospitalized (if hosp at least once) | 5.52 (9.99) | 5.98 (9.61) | 5.83 (10.94) | 6.42 (12.38) | 7.79 (14.44) | 8.42 (15.89) | 9.41 (17.18) | 9.66 (18.07) | 10.86 (18.57) | 10.68 (17.73) |
Income (DKK) | 123,945 (77,726) | 121,800 (75,051) | 192,523 (121,500) | 189,219 (116,759) | 217,822 (178,648) | 212,897 (173,192) | 239,396 (224,678) | 228,357 (160,773) | 212,304 (196,313) | 206,992 (146,882) |
Education | ||||||||||
Primary and lower secondary | 297,153 (36.69%) | 13,766 (44.89%) | 245,626 (29.11%) | 9,867 (34.99%) | 267,417 (34.43%) | 8,666 (38.93%) | 175,494 (38.05%) | 5,148 (42.98%) | 52,074 (45.40%) | 1,226 (47.26%) |
Upper and post-secondary | 435,834 (53.81%) | 14,422 (47.03%) | 383,077 (45.40%) | 12,027 (42.65%) | 324,811 (41.81%) | 8,762 (39.36%) | 187,931 (40.75%) | 4,423 (36.93%) | 42,703 (37.23%) | 931 (35.89%) |
Tertiary | 76,987 (9.50%) | 2,477 (8.08%) | 215,104 (25.49%) | 6,305 (22.36%) | 184,558 (23.76%) | 4,831 (21.70%) | 97,765 (21.20%) | 2,407 (20.10%) | 19,931 (17.38%) | 437 (16.85%) |
Occupational status | ||||||||||
Self-employed | 13,765 (1.70%) | 463 (1.51%) | 51,060 (6.05%) | 1,422 (5.04%) | 73,477 (9.46%) | 1,834 (8.24%) | 45,158 (9.79%) | 1,052 (8.78%) | 8,433 (7.35%) | 140 (5.40%) |
Employed | 611,023 (75.44%) | 22,030 (71.84%) | 668,622 (79.24%) | 21,350 (75.71%) | 593,681 (76.43%) | 16,070 (72.20%) | 316,158 (68.55%) | 7,673 (64.06%) | 37,438 (32.64%) | 888 (34.23%) |
Unemployed/others | 185,186 (22.86%) | 8,172 (26.65%) | 124,125 (14.71%) | 5,427 (19.25%) | 109,628 (14.11%) | 4,355 (19.57%) | 99,874 (21.66%) | 3,253 (27.16%) | 68,837 (60.01%) | 1,566 (60.37%) |
Marital status | ||||||||||
Married | 107,168 (13.23%) | 2,949 (9.62%) | 457,235 (54.19%) | 12,211 (43.30%) | 526,766 (67.81%) | 12,636 (56.77%) | 324,544 (70.37%) | 7,214 (60.23%) | 79,749 (69.52%) | 1,544 (59.52%) |
Cohabiting | 233,266 (28.80%) | 7,158 (23.34%) | 169,010 (20.03%) | 5,090 (18.05%) | 72,799 (9.37%) | 2,131 (9.57%) | 30,029 (6.51%) | 822 (6.86%) | 5,773 (5.03%) | 133 (5.13%) |
Single | 469,540 (57.97%) | 20,558 (67.04%) | 217,562 (25.78%) | 10,898 (38.65%) | 177,221 (22.81%) | 7,492 (33.66%) | 106,617 (23.12%) | 3,942 (32.91%) | 29,186 (25.44%) | 917 (35.35%) |
Urbanization | ||||||||||
> = 1000 Inh/km2 | 181,837 (22.45%) | 6,499 (21.19%) | 161,546 (19.14%) | 5,553 (19.69%) | 127,076 (16.36%) | 3,967 (17.82%) | 72,867 (15.80%) | 2,161 (18.04%) | 17,711 (15.44%) | 444 (17.12%) |
500-999 Inh/km2 | 144,758 (17.87%) | 5,371 (17.52%) | 135,991 (16.12%) | 4,387 (15.56%) | 124,759 (16.06%) | 3,478 (15.63%) | 74,472 (16.15%) | 1,911 (15.95%) | 18,459 (16.09%) | 438 (16.89%) |
200-499 Inh/km2 | 154,331 (19.05%) | 5,740 (18.72%) | 158,589 (18.79%) | 5,175 (18.35%) | 151,396 (19.49%) | 4,121 (18.51%) | 93,885 (20.36%) | 2,271 (18.96%) | 23,636 (20.61%) | 494 (19.04%) |
100-199 Inh/km2 | 108,477 (13.39%) | 4,273 (13.93%) | 121,933 (14.45%) | 4,092 (14.51%) | 117,405 (15.11%) | 3,270 (14.69%) | 69,050 (14.97%) | 1,729 (14.43%) | 16,727 (14.58%) | 348 (13.42%) |
50-99 Inh/km2 | 139,364 (17.21%) | 5,539 (18.06%) | 169,834 (20.13%) | 5,779 (20.49%) | 164,398 (21.16%) | 5,003 (22.48%) | 96,798 (20.99%) | 2,628 (21.94%) | 24,287 (21.17%) | 607 (23.40%) |
< 50 Inh/km2 | 81,207 (10.03%) | 3,243 (10.58%) | 95,914 (11.37%) | 3,213 (11.39%) | 91,752 (11.81%) | 2,420 (10.87%) | 54,118 (11.73%) | 1,278 (10.67%) | 13,888 (12.11%) | 263 (10.14%) |
Exposure time | 363.56 | 363.65 | 364.24 | 364.29 | 364.40 | 364.25 | 363.94 | 363.78 | 363.01 | 362.03 |
(days living in Denmark per year) | (19.43) | (18.96) | (15.50) | (15.35) | (14.31) | (15.72) | (17.97) | (18.44) | (23.85) | (29.29) |
Results
Sample description
Effects of oral clefts on hospitalizations
Age group/Cleft Measure | Hospitalization Probability | Hospitalization Days|Days > 0 | Total Effect on Hospitalization Days |
---|---|---|---|
Age 0-9 years | |||
Cleft Status | 0.168**** | 2.5**** | 1.05**** |
(0.003) | (0.17) | (0.02) | |
[195.1%] | [47.8%] | [233.2%] | |
{188.0%,202.1%} | {41.6%,54.0%} | {226.3%,241.3%} | |
Cleft lip | 0.099**** | 1.2**** | 0.6**** |
(0.004) | (0.2) | (0.03) | |
[115.0%] | [22.9%] | [133.2%] | |
{106.0%,124.1%} | {15.4%,30.4%} | {122.0%,143.9%} | |
Cleft lip with palate | 0.245**** | 3.37**** | 1.51**** |
(0.005) | (0.27) | (0.028) | |
[284.5%] | [64.4%] | [335.3%] | |
{273.5%,296.2%} | {54.3%,74.6%} | {324.0%,348.5%} | |
Cleft palate | 0.158**** | 2.38**** | 0.99**** |
(0.006) | (0.31) | (0.03) | |
[183.5%] | [45.5%] | [219.9%] | |
{170.3%,197.3%} | {34.0%,56.9%} | {206.3%,234.7%} | |
Age 10-19 years | |||
Cleft Status | 0.103**** | 1.03**** | 0.53**** |
(0.003) | (0.12) | (.01) | |
[183.6%] | [22.1%] | [202.3%] | |
{174.0%,193.7%} | {16.8%,27.2%} | {193.3%,212.6%} | |
Cleft lip | 0.043**** | 0.26 | 0.21**** |
(0.004) | (0.21) | (0.02) | |
[76.6%] | [5.6%] | [80.2%] | |
{63.1%,89.5%} | {-3.1%,14.3%} | {66.9%,94.3%} | |
Cleft lip with palate | 0.203**** | 1.43**** | 1.01**** |
(0.005) | (0.15) | (0.02) | |
[361.9%] | [30.6%] | [385.5%] | |
{344.9%,378.4%} | {24.4%,36.9%} | {368.9%,403.5%} | |
Cleft palate | 0.054**** | 0.63** | 0.28**** |
(0.004) | (0.28) | (0.02) | |
[96.3%] | [13.5%] | [106.9%] | |
{81.1%,111.9%} | {1.6%,25.4%} | {93.9%,123.0%} | |
Age 20-29 years | |||
Cleft Status | 0.038**** | 0.53*** | 0.26**** |
(0.003) | (0.2) | (0.02) | |
[32.6%] | [9.6%] | [40.4%] | |
{27.8%,37.1%} | {2.6%,16.7%} | {34.3%,46.1%} | |
Cleft lip | 0.014*** | 0.35 | 0.11*** |
(0.004) | (0.54) | (0.04) | |
[12.0%] | [6.3%] | [17.1%] | |
{4.2%,19.0%} | {-13.1%,25.8%} | {4.9%,28.8%} | |
Cleft lip with palate | 0.084**** | 0.43** | 0.5**** |
(0.005) | (0.17) | (0.03) | |
[72.0%] | [7.8%] | [77.6%] | |
{63.2%,80.6%} | {1.7%,14.0%} | {68.7%,85.8%} | |
Cleft palate | 0.015*** | 0.84** | 0.16**** |
(0.004) | (0.39) | (0.04) | |
[12.9%] | [15.2%] | [24.8%] | |
{5.2%,19.7%} | {1.4%,28.9%} | {14.0%,36.6%} | |
Age 30-39 years | |||
Cleft Status | 0.017**** | 0.51* | 0.15**** |
(0.003) | (0.27) | (0.02) | |
[15.3%] | [8.7%] | [23.2%] | |
{10.8%,19.9%} | {-0.5%,17.9%} | {15.7%,29.9%} | |
Cleft lip | 0.008* | 0.21 | 0.07* |
(0.004) | (0.41) | (0.04) | |
[7.2%] | [3.6%] | [10.8%] | |
{-0.5%,14.5%} | {-10.1%,17.4%} | {-0.6%,20.7%} | |
Cleft lip with palate | 0.038**** | 0.56 | 0.27**** |
(0.005) | (0.44) | (0.04) | |
[34.3%] | [9.6%] | [41.8%] | |
{26.4%,43.0%} | {-5.0%,24.3%} | {31.1%,54.0%} | |
Cleft palate | 0.003 | 0.72 | 0.09* |
(0.004) | (0.54) | (0.05) | |
[2.7%] | [12.3%] | [13.%] | |
{-4.7%,10.1%} | {-6.0%,30.6%} | {-2.0%,29.4%} | |
Age 40-49 years | |||
Cleft Status | 0.016**** | 0.75* | 0.19**** |
(0.003) | (0.42) | (0.03) | |
[18.8%] | [9.6%] | [28.7%] | |
{12.6%,25.9%} | {-1.0%,20.3%} | {18.5%,38.1%} | |
Cleft lip | -0.002 | 0.58 | 0.03 |
(0.004) | (0.71) | (0.06) | |
[-2.4%] | [7.4%] | [4.5%] | |
{-12.6%,8.0%} | {-10.3%,25.3%} | {-12.7%,23.0%} | |
Cleft lip with palate | 0.03**** | -0.36 | 0.2**** |
(0.005) | (0.49) | (0.04) | |
[35.3%] | [-4.6%] | [30.2%] | |
{23.3%,46.5%} | {-16.9%,7.7%} | {16.6%,42.6%} | |
Cleft palate | 0.019**** | 2.51** | 0.36**** |
(0.005) | (1.02) | (0.07) | |
[22.4%] | [32.2] | [54.4%] | |
{10.4%,34.6%} | {1.9%,57.9%} | {33.0%,74.6%} | |
Age 50-59 years | |||
Cleft Status | 0.013*** | 0.31 | 0.15*** |
(0.004) | (0.57) | (0.05) | |
[13.3%] | [3.3%] | [16.3%] | |
{5.3%,21.9%} | {-8.6%,15.2%} | {5.1%,28.2%} | |
Cleft lip | -0.001 | 1.43 | 0.13 |
(0.007) | (1.32) | (0.12) | |
[-1.0%] | [15.2%] | [14.1%] | |
{-14.5%,12.1%} | {-12.2%,42.5%} | {-12.2%,39.7%} | |
Cleft lip with palate | 0.025**** | 0.48 | 0.28*** |
(0.007) | (0.81) | (0.08) | |
[25.6%] | [5.1%] | [30.4%] | |
{11.5%,40.1%} | {-11.7%,21.8} | {12.5%,48.1%} | |
Cleft palate | 0.013* | -1.06 | 0.02 |
(0.007) | (0.84) | (0.09) | |
[13.3%] | [-11.3%] | [2.2%] | |
{-1.2%,28.0%} | {-28.8%,6.2%} | {-17.8%,21.8%} | |
Age 60-68 years | |||
Cleft Status | 0.002 | -0.3 | -0.01 |
(0.009) | (1.06) | (0.14) | |
[1.6%] | [-2.8%] | [-0.7%] | |
{-12.0%,15.7%} | {-21.9%,16.5%} | {-20.8%,19.1%} | |
Cleft lip | -0.022 | -2.25 | -0.52** |
(0.015) | (1.38) | (0.22) | |
[-17.1%] | [-20.7%] | [-37.1%] | |
{-39.3%,5.4%} | {-45.6%,4.2%} | {-67.8%,-6.2%} | |
Cleft lip with palate | 0.011 | -0.13 | 0.1 |
(0.014) | (1.51) | (0.23) | |
[8.5%] | [-1.2%] | [7.1%] | |
{-12.2%,29.6%} | {-28.5%,26.0%} | {-24.3%,39.0%} | |
Cleft palate | 0.013 | 1.04 | 0.27 |
(0.019) | (2.38) | (0.27) | |
[10.1%] | [9.6%] | [19.3%] | |
{-18.3%,38.9%} | {-33.3%,52.4%} | {-18.9%,57.8%} |
Effects on hospitalizations through socioeconomic status
Age group/Cleft Measure | Hospitalization Probability | Hospitalization Days|Days > 0 |
---|---|---|
Age 20-29 years | 0.036**** | 0.44** |
(0.003) | (0.19) | |
[30.8%] | [8.0%] | |
{26.5%,35.3%} | {1.0%,14.9%} | |
Age 30-39 years | 0.015**** | 0.22 |
(0.003) | (0.25) | |
[13.5%] | [3.8%] | |
{4.0%,15.8%} | {-5.2%,14.0%} | |
Age 40-49 years | 0.008*** | 0.34 |
(0.003) | (0.38) | |
[9.4%] | [4.4%] | |
{4.0%,15.8%} | {-5.2%,14.0%} | |
Age 50-59 years | 0.006 | -0.09 |
(0.004) | (0.52) | |
[6.1%] | [-1.0%] | |
{-1.3%,13.6%} | {-11.8%,9.9%} | |
Age 60-68 years | -0.003 | -0.77 |
(0.009) | (0.98) | |
[-2.3%] | [-7.1%] | |
{-15.0%,11.1%} | {-24.7%,10.5%} |
Age group/Cleft Measure | Hospitalization Probability | Hospitalization Days|Days > 0 | Total Effect on Hospitalization Days |
---|---|---|---|
Age 0-9 years | |||
Cleft Status | 0.171**** | 2.55**** | 1.08**** |
(0.003) | (0.17) | (0.018) | |
[198.6%] | [48.8%] | [240%] | |
{191.7%,205.8%} | {42.6%,55.1%} | {233.1%,248.4%} | |
Cleft lip | 0.099**** | 1.207**** | 0.60**** |
(0.004) | (0.200) | (0.02) | |
[115.0%] | [23.1%] | [133.3%] | |
{105.7%,124.0%} | {15.6%,30.6%} | {123.6%,144.9%} | |
Cleft lip with palate | 0.248**** | 3.420**** | 1.55**** |
(0.005) | (0.271) | (0.03) | |
[288.0%] | [65.4%] | [344.4%] | |
{276.7%,299.1%} | {55.3%,75.5%} | {330.4%,356.4%} | |
Cleft palate | 0.166**** | 2.488**** | 1.05**** |
(0.006) | (0.316) | (0.03) | |
[192.8%] | [47.6%] | [233.3%] | |
{178.5%,206.3%} | {35.7%,59.4%} | {219.3%,247.0%} | |
Age 10-19 years | |||
Cleft Status | 0.107**** | 1.05**** | 0.55**** |
(0.003) | (0.12) | (0.01) | |
[190.7%] | [22.5%] | [210.0%] | |
{181.0%,201.1%} | {17.2%,27.6%} | {202.3%,221.3%} | |
Cleft lip | 0.045**** | 0.261 | 0.22**** |
(0.004) | (0.210) | (0.02) | |
[80.2%] | [5.6%] | [84.0%] | |
{66.0%,92.9%} | {-3.2%,14.4%} | {69.9%,98.5%} | |
Cleft lip with palate | 0.208**** | 1.445**** | 1.04**** |
(0.005) | (0.144) | (0.02) | |
[370.8%] | [30.9%] | [396.9%] | |
{354.5%,387.5%} | {24.9%,37.0%} | {379.9%,416.5%} | |
Cleft palate | 0.058**** | 0.675** | 0.31**** |
(0.005) | (0.289) | (0.02) | |
[103.4%] | [14.5%] | [118.3%] | |
{87.8%,120.0%} | {2.3%,26.6%} | {101.4%,133.4%} | |
Age group/Cleft Measure | Hospitalization Probability | Hospitalization Days|Days > 0 | Total Effect on Hospitalization Days |
Age 0-9 years | |||
Cleft Status | 0.171**** | 2.55**** | 1.08**** |
(0.003) | (0.17) | (0.018) | |
[198.6%] | [48.8%] | [240%] | |
{191.7%,205.8%} | {42.6%,55.1%} | {233.1%,248.4%} | |
Cleft lip | 0.099**** | 1.207**** | 0.60**** |
(0.004) | (0.200) | (0.02) | |
[115.0%] | [23.1%] | [133.3%] | |
{105.7%,124.0%} | {15.6%,30.6%} | {123.6%,144.9%} | |
Cleft lip with palate | 0.248**** | 3.420**** | 1.55**** |
(0.005) | (0.271) | (0.03) | |
[288.0%] | [65.4%] | [344.4%] | |
{276.7%,299.1%} | {55.3%,75.5%} | {330.4%,356.4%} | |
Cleft palate | 0.166**** | 2.488**** | 1.05**** |
(0.006) | (0.316) | (0.03) | |
[192.8%] | [47.6%] | [233.3%] | |
{178.5%,206.3%} | {35.7%,59.4%} | {219.3%,247.0%} | |
Age 10-19 years |
Discussion
0-9 years of age | 10-19 years of age | |||
---|---|---|---|---|
Including controls with malformations | Excluding controls with malformations | Including controls with malformations | Excluding controls with malformations | |
Number of observations | 618,082 | 586,874 | 343,797 | 326,991 |
Hospitalized at least once | 54,562 (8.83%) | 48,280 (8.23%) | 16,967 (4.94%) | 15,791 (4.83%) |
Hospitalization days among those hospitalized | 5.23 (11.37) | 4.68 (9.73) | 3.88 (9.27) | 3.83 (9.39) |