Background
Methods
Study population and design
The HELIUS cohort
The COVID-19 serological sub-study
The online COVID-19 sub-study
Linkage to PCR test results
Ethical approval and informed consent
Measurements
SARS-CoV-2 infection status
Pre-pandemic factors
Intra-pandemic COVID-19 risk aggravating activities
Intra-pandemic COVID-19 risk mitigating activities
Other measurements
Statistical analysis
Sensitivity analyses
Results
Baseline characteristics
Variable name & categories | Total N = 8595 | Dutch origin N = 2038 | South Asian Surinamese origin N = 1316 | African Surinamese origin N = 1605 | Ghanaian origin N = 501 | Turkish origin N = 1578 | Moroccan origin N = 1557 |
---|---|---|---|---|---|---|---|
N (%)
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N (%)
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N (%)
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N (%)
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N (%)
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N (%)
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N (%)
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Sex
| |||||||
Females | 5048(58.7) | 1130(55.4) | 750(57.0) | 1024(63.8) | 305(60.9) | 884(56.0) | 955(61.3) |
Males | 3547(41.3) | 908(44.6) | 566(43.0) | 581(36.2) | 196(39.1) | 694(44.0) | 602(38.7) |
Age in years (as of 1 February 2021) | |||||||
Mean age (SD) | 49.8(13.1) | 51.4(13.7) | 51.9(13.3) | 53.8(12.4) | 50.5(11.4) | 46.1(11.7) | 45.3(12.3) |
24–29 years | 707(8.2) | 114(5.6) | 95(7.2) | 70(4.4) | 38(7.6) | 185(11.7) | 205(13.2) |
30–34 years | 758(8.8) | 197(9.7) | 99(7.5) | 96(6.0) | 30(6.0) | 150(9.5) | 186(11.9) |
35–39 years | 838(9.7) | 220(10.8) | 109(8.3) | 116(7.2) | 33(6.6) | 173(11.0) | 187(12.0) |
40–44 years | 838(9.7) | 189(9.3) | 94(7.1) | 117(7.3) | 44(8.8) | 195(12.4) | 199(12.8) |
45–49 years | 939(10.9) | 201(9.9) | 123(9.3) | 137(8.5) | 56(11.2) | 207(13.1) | 215(13.8) |
50–54 years | 1136(13.2) | 221(10.8) | 177(13.4) | 204(12.7) | 85(17.0) | 259(16.4) | 190(12.2) |
55–59 years | 1256(14.6) | 243(11.9) | 214(16.3) | 285(17.8) | 108(21.6) | 244(15.5) | 162(10.4) |
60–64 years | 1022(11.9) | 256(12.6) | 186(14.1) | 283(17.6) | 80(16.0) | 106(6.7) | 111(7.1) |
65–69 years | 625(7.3) | 206(10.1) | 123(9.3) | 179(11.2) | 20(4.0) | 35(2.2) | 62(4.0) |
70–74 years | 389(4.5) | 159(7.8) | 76(5.8) | 92(5.7) | 7(1.4) | 21(1.3) | 34(2.2) |
75–79 years | 87(1.0) | 32(1.6) | 20(1.5) | 26(1.6) | 0(0.0) | 3(0.2) | 6(0.4) |
Education
| |||||||
No school/Low education | 1216(14.1) | 57(2.8) | 168(12.8) | 67(4.2) | 122(24.4) | 435(27.6) | 367(23.6) |
Lower secondary education | 2075(24.1) | 241(11.8) | 443(33.7) | 521(32.5) | 176(35.1) | 405(25.7) | 289(18.6) |
Upper secondary education | 2644(30.8) | 439(21.5) | 400(30.4) | 595(37.1) | 163(32.5) | 479(30.4) | 568(36.5) |
Tertiary/higher vocational education | 2602(30.3) | 1293(63.4) | 299(22.7) | 409(25.5) | 34(6.8) | 247(15.7) | 320(20.6) |
Occupation
| |||||||
Elementary Occupation | 890(10.4) | 24(1.2) | 123(9.3) | 98(6.1) | 244(48.7) | 228(14.4) | 173(11.1) |
Lower occupation | 2163(25.2) | 280(13.7) | 393(29.9) | 469(29.2) | 126(25.1) | 487(30.9) | 408(26.2) |
Medium occupation | 2057(23.9) | 434(21.3) | 370(28.1) | 538(33.5) | 45(9.0) | 307(19.5) | 363(23.3) |
Higher occupation | 1625(18.9) | 739(36.3) | 221(16.8) | 304(18.9) | 17(3.4) | 135(8.6) | 209(13.4) |
Scientific occupation | 629(7.3) | 417(20.5) | 57(4.3) | 52(3.2) | 8(1.6) | 57(3.6) | 38(2.4) |
Migration generation
| |||||||
1st generation | 4892(56.9) | NA | 990(75.2) | 1311(81.7) | 463(92.4) | 1096(69.5) | 1032(66.3) |
2nd generation | 1665(19.4) | NA | 326(24.8) | 294(18.3) | 38(7.6) | 482(30.5) | 525(33.7) |
No migration history | 2038(23.7) | 2038(100) | NA | NA | NA | NA | NA |
Health literacy
| |||||||
Health literacy adequate | 7558(87.9) | 2024(99.3) | 1224(93.0) | 1557(97.0) | 346(69.1) | 1159(73.4) | 1248(80.2) |
Health literacy not adequate | 1005(11.7) | 14(0.7) | 87(6.6) | 45(2.8) | 149(29.7) | 408(25.9) | 302(19.4) |
Household size
| |||||||
1 person household | 1546(18.0) | 520(25.5) | 268(20.4) | 435(27.1) | 67(13.4) | 115(7.3) | 141(9.1) |
2-person household | 1998(23.2) | 772(37.9) | 302(22.9) | 403(25.1) | 106(21.2) | 218(13.8) | 197(12.7) |
3-person household | 1651(19.2) | 339(16.6) | 293(22.3) | 340(21.2) | 125(25.0) | 318(20.2) | 236(15.2) |
4-person household | 1766(20.5) | 318(15.6) | 277(21.0) | 263(16.4) | 112(22.4) | 474(30.0) | 322(20.7) |
5-person household + | 1553(18.1) | 84(4.1) | 166(12.6) | 141(8.8) | 82(16.4) | 437(27.7) | 643(41.3) |
Underlying health conditions
1
| |||||||
Underlying health conditions on medications | 1003(11.7) | 213(10.5) | 203(15.4) | 245(15.3) | 60(12.0) | 174(11.0) | 108(6.9) |
Underlying health conditions not on medications | 3700(43.0) | 579(28.4) | 600(45.6) | 824(51.3) | 287(57.3) | 749(47.5) | 661(42.5) |
No underlying health conditions | 3892(45.3) | 1246(61.1) | 513(39.0) | 536(33.4) | 154(30.7) | 655(41.5) | 788(50.6) |
Physical activity
2
| |||||||
Met recommendations | 4884(56.8) | 1562(76.6) | 693(52.7) | 955(59.5) | 291(58.1) | 640(40.6) | 743(47.7) |
Did not meet recommendation | 3701(43.1) | 474(23.3) | 621(47.2) | 650(40.5) | 210(41.9) | 935(59.3) | 811(52.1) |
Smoking
| |||||||
Current | 2022(23.5) | 503(24.7) | 354(26.9) | 456(28.4) | 21(4.2) | 502(31.8) | 186(11.9) |
Never | 4700(54.7) | 747(36.7) | 763(58.0) | 846(52.7) | 424(84.6) | 749(47.5) | 1171(75.2) |
Past | 1840(21.4) | 783(38.4) | 191(14.5) | 300(18.7) | 54(10.8) | 317(20.1) | 195(12.5) |
Alcohol consumption
| |||||||
Yes | 4464(51.9) | 1875(92.0) | 743(56.5) | 1108(69.0) | 277(55.3) | 351(22.2) | 110(7.1) |
No | 4095(47.6) | 162(7.9) | 566(43.0) | 489(30.5) | 221(44.1) | 1216(77.1) | 1441(92.5) |
Fruit intake per week
| |||||||
mean (SD) | 7.29(4.7) | 7.64(4.7) | 7.32(4.8) | 7.28(4.8) | 6.17(4.6) | 7.43(4.7) | 7.04(4.7) |
SARS-Cov-2 PCR test result
| |||||||
COVID-19 PCR positive | 2603(30.3) | 307(15.1) | 388(29.5) | 483(30.1) | 140(27.9) | 618(39.2) | 667(42.8) |
COVID-19 PCR negative | 5992(69.7) | 1731(84.9) | 928(70.5) | 1122(69.9) | 361(72.1) | 960(60.8) | 890(57.2) |
COVID-19 waves
| |||||||
Pre-second wave (June - September 2020) | 858(10.0) | 165(8.1) | 123(9.3) | 163(10.2) | 35(7.0) | 151(9.6) | 221(14.2) |
Second wave (September 2020 -June 2021) | 5855(68.1) | 1480(72.6) | 916(69.6) | 997(62.1) | 358(71.5) | 1111(70.4) | 993(63.8) |
Post-second wave (June - September 2021) | 1841(21.4) | 387(19.0) | 269(20.4) | 438(27.3) | 103(20.6) | 306(19.4) | 338(21.7) |
Intra-pandemic activities
Variable name & Categories | Total N = 714 | Dutch origin N = 206 | South Asian Surinamese origin N = 151 | African Surinamese origin N = 119 | Ghanaian origin N = 38 | Turkish origin N = 102 | Moroccan origin N = 98 |
---|---|---|---|---|---|---|---|
N (%) | N (%) | N (%) | N (%) | N (%) | N (%) | N (%) | |
Went for grocery shopping during coronavirus pandemic
| |||||||
Yes | 650(91.0) | 195(94.7) | 128(84.8) | 112(94.1) | 30(78.9) | 91(89.2) | 94(92.5) |
No | 63(8.8) | 11(5.3) | 22(14.6) | 7(5.9) | 8(21.1) | 11(10.8) | 4(7.5) |
Visited family or friends during coronavirus pandemic
| |||||||
Yes | 356(49.9) | 134(65.0) | 57(37.7) | 49(41.2) | 8(21.1) | 53(52.0) | 55(56.1) |
No | 357(50.0) | 72(35.0) | 93(61.6) | 70(58.8) | 30(78.9) | 49(48.0) | 43(43.9) |
Walked the dog or to played outside with your children during coronavirus pandemic
| |||||||
Yes | 116(16.2) | 52(25.2) | 8(5.3) | 7(5.9) | 3(7.9) | 23(22.5) | 23(23.5) |
No | 597(83.6) | 154(74.8) | 142(94.0) | 112(94.1) | 35(92.1) | 79(77.5) | 75(76.5) |
Went outside to get some fresh air or exercise during coronavirus pandemic
| |||||||
Yes | 455(63.7) | 159(77.2) | 87(57.6) | 64(53.8) | 19(50.0) | 68(66.7) | 58(59.2) |
No | 258(36.1) | 47(22.8) | 63(41.7) | 55(46.2) | 19(50.0) | 34(33.3) | 40(40.8) |
Went outside to take care of someone, such as informal care or shopping during coronavirus pandemic
| |||||||
Yes | 102(14.3) | 37(18.0) | 17(11.3) | 17(14.3) | 0(0.0) | 12(11.8) | 19(19.4) |
No | 611(85.6) | 169(82.0) | 133(88.1) | 102(85.7) | 38(100.0) | 90(88.2) | 79(80.6) |
Went to pick up your medication or to visit the doctor during coronavirus pandemic
| |||||||
Yes | 168(23.5) | 35(17.0) | 37(24.5) | 31(26.1) | 12(31.6) | 34(33.3) | 19(19.4) |
No | 545(76.3) | 171(83.0) | 113(74.8) | 88(73.9) | 26(68.4) | 68(66.7) | 79(80.6) |
Visited the church/mosque/place of worship during coronavirus pandemic
| |||||||
Yes | 55(7.7) | 3(1.5) | 10(6.6) | 9(7.6) | 11(28.9) | 13(12.7) | 9(9.2) |
No | 658(92.2) | 203(98.5) | 140(92.7) | 110(92.4) | 27(71.1) | 89(87.3) | 89(90.8) |
Visited the cinema, theatre, concert, or museum during coronavirus pandemic
| |||||||
Yes | 16(2.2) | 13(6.3) | 2(1.3) | 1(0.8) | 0(0.0) | 0(0.0) | 0(0.0) |
No | 697(97.6) | 193(93.7) | 148(98.0) | 118(99.2) | 38(100.0) | 102(100.0) | 98(100.0) |
Visited a catering facility (bar/restaurant) during coronavirus pandemic
| |||||||
Yes | 9(1.3) | 5(2.4) | 1(0.7) | 1(0.8) | 0(0.0) | 2(2.0) | 0(0.0) |
No | 704(98.6) | 201(97.6) | 149(98.7) | 118(99.2) | 38(100.0) | 100(98.0) | 98(100.0) |
Exercised indoors (e.g., visited a sports club/gym) during coronavirus pandemic
| |||||||
Yes | 81(11.3) | 159(77.2) | 87(57.6) | 64(53.8) | 19(50.0) | 68(66.7) | 58(59.2) |
No | 632(88.5) | 47(22.8) | 63(41.7) | 55(46.2) | 19(50.0) | 34(33.3) | 40(40.8) |
Visited a recreational area (e.g., forest, beach, or campsite) during coronavirus pandemic
| |||||||
Yes | 117(16.4) | 66(32.0) | 19(12.6) | 5(4.2) | 2(5.3) | 9(8.8) | 16(16.3) |
No | 596(83.5) | 140(68.0) | 131(86.8) | 114(95.8) | 36(94.7) | 93(91.2) | 82(83.7) |
Went outside for any other reason during coronavirus pandemic
| |||||||
Yes | 168(23.5) | 59(28.6) | 37(24.5) | 25(21.0) | 1(2.6) | 21(20.6) | 25(25.5) |
No | 545(76.3) | 147(71.4) | 113(74.8) | 94(79.0) | 37(97.4) | 81(79.4) | 73(74.5) |
Used public transport during coronavirus pandemic
| |||||||
Yes | 222(31.1) | 58(28.2) | 39(25.8) | 53(44.5) | 13(34.2) | 22(21.6) | 37(37.8) |
No | 491(68.8) | 148(71.8) | 111(73.5) | 66(55.5) | 25(65.8) | 80(78.4) | 61(62.2) |
Received visitors at home during coronavirus pandemic
| |||||||
Yes | 377(52.8) | 133(64.6) | 73(48.3) | 59(49.6) | 9(23.7) | 56(54.9) | 47(48.0) |
No | 336(47.1) | 73(35.4) | 77(51.0) | 60(50.4) | 29(76.3) | 46(45.1) | 51(52.0) |
Went to work during coronavirus Pandemic
| |||||||
Yes | 364(51.0) | 100(48.5) | 75(49.7) | 59(49.6) | 19(50.0) | 54(52.9) | 57(58.2) |
No | 350(49.0) | 106(51.5) | 76(50.3) | 60(50.4) | 19(50.0) | 48(47.1) | 41(41.8) |
Total number of daily activities during coronavirus pandemic
| |||||||
mean (SD) | 5.6(1.7) | 6.3(1.6) | 5.0(1.8) | 5.2(1.7) | 4.4(1.6) | 5.5(1.6) | 5.8(1.6) |
Vaccinated against COVID-19
| |||||||
Yes | 212(29.7) | 71(34.5) | 54(35.8) | 30(25.4) | 7(18.4) | 28(27.5) | 22(22.4) |
No | 511(70.3) | 135(65.5) | 97(64.2) | 88(74.6) | 31(81.6) | 74(72.5) | 76(77.6) |
Previous COVID-19 infection
| |||||||
Yes | 53(7.45) | 14(6.8) | 8(5.3) | 5(4.2) | 13(34.2) | 9(8.8) | 4(4.1) |
No | 658(92.5) | 191(93.2) | 142(94.7) | 113(95.8) | 25(65.8) | 93(0.912) | 94(95.9) |
Variable name & Categories | Total N = 553 | Dutch origin N = 253 | South Asian Surinamese origin N = 73 | African Surinamese origin N = 95 | Ghanaian origin N = 12 | Turkish origin N = 60 | Moroccan origin N = 60 |
---|---|---|---|---|---|---|---|
N (%) | N (%) | N (%) | N (%) | N (%) | N (%) | N (%) | |
How difficult or easy is it for you to regularly wash your hands for 20 s with soap and water?
| |||||||
Very easy + easy | 425(76.9) | 190(75.1) | 56(76.7) | 78(82.1) | 9(75.0) | 49(81.7) | 43(71.7) |
Very difficult + difficult + neutral | 107(19.3) | 60(23.7) | 15(20.5) | 14(14.7) | 1(8.3) | 7(11.7) | 10(16.7) |
How difficult or easy is it for you to always cough or sneeze into your elbow (instead of into your hand or in the air)?
| |||||||
Very easy + easy | 444(80.3) | 214(84.6) | 51(69.9) | 78(82.1) | 8(66.7) | 51(85.0) | 42(70.0) |
Very difficult + difficult + neutral | 88(15.9) | 36(14.2) | 20(27.4) | 14(14.7) | 2(16.7) | 5(8.3) | 11(18.3) |
How difficult or easy is it for you to always use a paper tissue to wipe or blow your nose (instead of your sleeve or your hand, or a cotton handkerchief)?
| |||||||
Very easy + easy | 448(81.0) | 194(76.7) | 60(82.2) | 87(91.6) | 8(66.7) | 52(86.7) | 47(78.3) |
Very difficult + difficult + neutral | 84(15.2) | 56(22.1) | 11(15.1) | 5(5.3) | 2(16.7) | 4(6.7) | 6(10.0) |
How difficult or easy is it for you to stay at home as much as possible?
| |||||||
Very easy + easy | 220(39.8) | 91(36.0) | 33(45.2) | 50(52.6) | 4(33.3) | 23(38.3) | 19(31.7) |
Very difficult + difficult + neutral | 312(56.4) | 159(62.8) | 38(52.1) | 42(44.2) | 6(50.0) | 33(55.0) | 34(56.7) |
How difficult or easy is it for you to always stay 1.5 m away from other people (except within your family/household)?
| |||||||
Very easy + easy | 207(37.4) | 79(31.2) | 31(42.5) | 48(50.5) | 6(50.0) | 23(38.3) | 20(33.3) |
Very difficult + difficult + neutral | 325(58.8) | 171(67.6) | 40(54.8) | 44(46.3) | 4(33.3) | 33(55.0) | 33(55.0) |
How difficult or easy is it for you to not visit people whose health is already at risk of COVID-19?
| |||||||
Very easy + easy | 331(59.9) | 133(52.6) | 46(63.0) | 75(78.9) | 7(58.3) | 40(66.7) | 30(50.0) |
Very difficult + difficult + neutral | 201(36.3) | 117(46.2) | 25(34.2) | 17(17.9) | 3(25.0) | 16(26.7) | 23(38.3) |
How difficult or easy is it for you to not shake hands?
| |||||||
Very easy + easy | 460(83.2) | 219(86.6) | 57(78.1) | 79(83.2) | 7(58.3) | 50(83.3) | 48(80.0) |
Very difficult + difficult + neutral | 72(13.0) | 31(12.3) | 14(19.2) | 13(13.7) | 3(25.0) | 6(10.0) | 5(8.3) |
How difficult or easy is it for you to wear a face mask in public?
| |||||||
Very easy + easy | 361(65.3) | 166(65.6) | 47(64.4) | 70(73.7) | 8(66.7) | 43(71.7) | 27(45.0) |
Very difficult + difficult + neutral | 171(30.9) | 84(33.2) | 24(32.9) | 22(23.2) | 2(16.7) | 13(21.7) | 26(43.3) |
Age and sex adjusted proportions of SARS-CoV-2 infections
Relative contributions of pre-pandemic factors and intra-pandemic activities to SARS-CoV-2 infections between migrants and non-migrants
Variable | Number per group (N) | Actual population prevalence in Amsterdam (%) | Model 1 PR (95% CI) | Model 1 PAF (%) | Model 2 PR (95% CI) | Model 2 PAF (%) |
---|---|---|---|---|---|---|
Pre-pandemic socio-demographic and medical factors (explanatory factors) | ||||||
Dutch origin | 2038 | 43.83 | 1.00 (ref) | ref | 1.00(ref) | ref |
South Asian Surinamese origin | 1316 | 3.65 | 1.95(1.68–2.27) | 3.35 | 1.63(1.39–1.93) | 2.25 |
African Surinamese origin | 1605 | 3.65 | 2.00(1.74–2.31) | 3.52 | 1.71(1.46–2.01) | 2.53 |
Ghanaian origin | 501 | 1.49 | 1.83(1.49–2.23) | 1.22 | 1.45(1.14–1.83) | 0.67 |
Turkish origin | 1578 | 5.08 | 2.55(2.23–2.93) | 7.30 | 1.95(1.66–2.32) | 4.60 |
Moroccan origin | 1557 | 8.87 | 2.80(2.45–3.22) | 13.77 | 2.20(1.87–2.59) | 9.62 |
Pre-pandemic lifestyle factors (explanatory factors) | ||||||
Dutch origin | 2038 | 43.83 | 1.00 (ref) | ref | 1.00 (ref) | ref |
South Asian Surinamese origin | 1316 | 3.65 | 1.95(1.68–2.27) | 3.35 | 1.79(1.53–2.11) | 2.80 |
African Surinamese origin | 1605 | 3.65 | 2.00(1.74–2.31) | 3.52 | 1.93(1.66–2.25) | 3.28 |
Ghanaian origin | 501 | 1.49 | 1.83(1.49–2.23) | 1.22 | 1.64(1.31–2.02) | 0.94 |
Turkish origin | 1578 | 5.08 | 2.55(2.23–2.93) | 7.30 | 2.29(1.96–2.70) | 6.15 |
Moroccan origin | 1557 | 8.87 | 2.80(2.45–3.22) | 13.77 | 2.35(1.99–2.78) | 10.70 |
Intra-pandemic COVID-19 risk aggravating activities (explanatory factors) | ||||||
Dutch origin | 206 | 43.83 | 1.00 (ref) | ref | 1.00 (ref) | ref |
South Asian Surinamese origin | 151 | 3.65 | 1.24(1.05–1.48) | 0.87 | 1.21(1.06–1.46) | 0.76 |
African Surinamese origin | 119 | 3.65 | 1.22(1.01–1.46) | 0.80 | 1.19(1.05–1.43) | 0.69 |
Ghanaian origin | 38 | 1.49 | 0.92(0.66–1.24) | NA | 0.91(0.62–1.21) | NA |
Turkish origin | 102 | 5.08 | 1.33(1.10–1.61) | 1.65 | 1.31(1.06–1.61) | 1.55 |
Moroccan origin | 98 | 8.87 | 1.43(1.18–1.73) | 3.68 | 1.39(1.14–1.69) | 3.35 |
Intra-pandemic COVID-19 risk mitigating activities (explanatory factors) | ||||||
Dutch origin | 253 | 43.83 | 1.00 (ref) | ref | 1.00 (ref) | ref |
South Asian Surinamese origin | 73 | 3.65 | 1.14(1.01–1.42) | 0.51 | 1.18(0.94–1.47) | 0.65 |
African Surinamese origin | 95 | 3.65 | 1.38(1.20–1.89) | 1.37 | 1.39(1.13–1.69) | 1.40 |
Ghanaian origin | 12 | 1.49 | Excluded | Excluded | Excluded | Excluded |
Turkish origin | 60 | 5.08 | 1.50(1.20–1.89) | 2.48 | 1.51(1.19–1.91) | 2.53 |
Moroccan origin | 60 | 8.87 | 1.49(1.18–1.88) | 4.17 | 1.47(1.13–1.86) | 4.00 |