Table 1.
Characteristics of the sample as a whole and by access to nasopharyngeal swab.
| Nasopharyngeal swab |
||||
|---|---|---|---|---|
| All n = 126,741) | Not done (n = 120,605) | Done (n = 6136) | p-value | |
| Age (years) | 46.29 (14.10) | 46.28 (14.16) | 46.43 (12.80) | 0.411 |
| Age ≥65 years | 13,455 (10.6) | 13,071 (10.8) | 384 (6.3) | <0.001 |
| Sex (M) | 48,008 (37.9) | 45,858 (38.0) | 2150 (35.0) | <0.001 |
| Educational level | <0.001 | |||
| Low | 6659 (5.3) | 6414 (5.3) | 245 (4.0) | |
| Middle | 42,418 (33.5) | 41,113 (34.1) | 1305 (21.3) | |
| High | 77,664 (61.3) | 73,078 (60.6) | 4586 (74.7) | |
| Occupation | <0.001 | |||
| Employed | 90,952 (71.8) | 85,552 (70.9) | 5400 (88.0) | |
| Student | 9279 (7.3) | 9103 (7.5) | 176 (2.9) | |
| Unemployed | 6049 (4.8) | 5944 (4.9) | 105 (1.7) | |
| Retired | 13,641 (10.8) | 13,355 (11.1) | 286 (4.7) | |
| Other | 6820 (5.4) | 6651 (5.5) | 169 (2.8) | |
| Healthcare professional | 11,657 (9.2) | 8431 (7.0) | 3226 (52.6) | <0.001 |
| Smoking habit | <0.001 | |||
| Never | 72,284 (57.0) | 68,489 (56.8) | 3795 (61.8) | |
| Former | 30,427 (24.0) | 29,059 (24.1) | 1368 (22.3) | |
| Current | 24,030 (19.0) | 23,057 (19.1) | 973 (15.9) | |
| Chronic diseases (number) | 0.325 | |||
| 0 | 71,631 (56.5) | 68,158 (56.5) | 3473 (56.6) | |
| 1 | 31,202 (24.6) | 29,657 (24.6) | 1545 (25.2) | |
| 2+ | 23,908 (18.9) | 22,790 (18.9) | 1118 (18.2) | |
| Respiratory diseases | 8505 (6.7) | 8031 (6.7) | 474 (7.7) | 0.001 |
| Cardiovascular diseases | 8921 (7.0) | 8547 (7.1) | 374 (6.1) | 0.003 |
| Arterial hypertension | 19,084 (15.1) | 18,102 (15.0) | 982 (16.0) | 0.035 |
| Diabetes pharmacologically treated | 2575 (2.0) | 2449 (2.0) | 126 (2.1) | 0.938 |
| Chronic kidney diseases | 1086 (0.9) | 1040 (0.9) | 46 (0.7) | 0.388 |
| Immunologic diseases | 12,310 (9.7) | 11,718 (9.7) | 592 (9.6) | 0.878 |
| Cancer | 3819 (3.0) | 3644 (3.0) | 175 (2.9) | 0.472 |
| Metabolic diseases | 10,903 (8.6) | 10,408 (8.6) | 495 (8.1) | 0.131 |
| Liver diseases | 972 (0.8) | 930 (0.8) | 42 (0.7) | 0.494 |
| Depression-anxiety | 11,478 (9.1) | 11,059 (9.2) | 419 (6.8) | <0.001 |
| Self-reported symptoms and conditions | ||||
| None | 6941 (5.5) | 5947 (4.9) | 994 (16.2) | <0.001 |
| Fever | 16,717 (13.2) | 14,829 (12.3) | 1888 (30.8) | <0.001 |
| Cough | 42,082 (33.2) | 39,670 (32.9) | 2412 (39.3) | <0.001 |
| Headache | 55,096 (43.5) | 52,440 (43.5) | 2656 (43.3) | 0.774 |
| Myalgia | 39,395 (31.1) | 36,912 (30.6) | 2483 (40.5) | <0.001 |
| Olfactory or taste disorders | 11,065 (8.7) | 9572 (7.9) | 1493 (24.3) | <0.001 |
| Shortness of breath | 10,867 (8.6) | 9820 (8.1) | 1047 (17.1) | <0.001 |
| Sore throat/rhinorrhea | 64,871 (51.2) | 62,240 (51.6) | 2631 (42.9) | <0.001 |
| Chest pain | 13,221 (10.4) | 12,213 (10.1) | 1008 (16.4) | <0.001 |
| Feeling of fast beating | 12,545 (9.9) | 11,636 (9.6) | 909 (14.8) | <0.001 |
| Gastrointestinal disturbances | 33,223 (26.2) | 31,211 (25.9) | 2012 (32.8) | <0.001 |
| Conjunctivitis | 18,882 (14.9) | 18,038 (15.0) | 844 (13.8) | 0.010 |
| Pneumonia | 1156 (0.9) | 595 (0.5) | 561 (9.1) | <0.001 |
| Month at symptoms’ onset | <0.001 | |||
| No symptoms | 6941 (5.5) | 5947 (4.9) | 994 (16.2) | |
| February | 64,967 (51.3) | 63,192 (52.4) | 1775 (28.9) | |
| March | 46,842 (37.0) | 43,874 (36.4) | 2968 (48.4) | |
| April | 7953 (6.3) | 7560 (6.3) | 393 (6.4) | |
| May | 38 (0.0) | 32 (0.0) | 6 (0.1) | |
| Criteria | <0.001 | |||
| Epidemiological | 6941 (5.5) | 5947 (4.9) | 994 (16.2) | |
| Clinical | 98,683 (77.9) | 97,196 (80.6) | 1487 (24.2) | |
| Epidemiological and clinical | 21,117 (16.7) | 17,462 (14.5) | 3655 (59.6) | |
| Contact with physicians to report symptoms of suspected COVID-19 | 18,974 (15.0) | 15,910 (13.2) | 3064 (49.9) | <0.001 |
| Area of residence | <0.001 | |||
| Area 1 | 76,692 (61.0) | 73,197 (61.2) | 3495 (57.6) | |
| Area 2 | 14,886 (11.8) | 14,166 (11.8) | 720 (11.9) | |
| Area 3 | 26,458 (21.1) | 24,933 (20.8) | 1525 (25.1) | |
| Area 4 | 7321 (5.8) | 7013 (5.9) | 308 (5.1) | |
| Other | 297 (0.2) | 280 (0.2) | 17 (0.3) | |
Notes: Number are mean (SD) for the continuous variables and frequency (%) for the categorical ones. P-values refer to the Student t-test (for continuous variables) or chi-square test (for categoric variables) to compare the characteristics of individuals who performed vs. did not perform nasopharyngeal swab. Area 1 includes Piedmont, Lombardy, Emilia Romagna, Liguria, Marche, and Aosta Valley. Area 2 includes Tuscany, Trentino Alto Adige, and Apulia. Area 3 includes Veneto, Lazio, Friuli Venezia Giulia, Molise, and Campania. Area 4 includes Sicily, Sardinia, Umbria, Calabria, and Basilicata. Other includes the Republic of San Marino, other countries, and unknown.