Characteristic Sampled Arm 1: Mail + Phone Arm 2: Paper Invite + Email (x2) + Mail (x2) Arm 3: Paper Invite + Email (x3) + Mail Arm 4: Email (x4) + Phone Arm 5: Email (x4) + Mail + Phone Arm 6: Email (x4) + Mail (x2) Arm 7: Text + Email + Text + Email + Mail (x2) Arm 8: Paper Invite + Text + Email (x2)+ Mail Arm 9: Paper Invite (URL only) + Email (x2)+ Mail (x2) Chi-squared P-value
N (%) N (%) N (%) N (%) N (%) N (%) N (%) N (%) N (%) N (%)
Age
18-24 4114 (15.4%) 64 (8.8%) 20 (4.4%) 8 (2.2%) 72 (9.9%) 83 (9.9%) 15 (3.3%) 33 (5.5%) 31 (7.7%) 22 (5.5%) <0.001
25-34 6175 (23.1%) 104 (15.4%) 39 (8.8%) 37 (9.9%) 108 (15.4%) 123 (15.4%) 43 (8.8%) 54 (9.9%) 39 (9.9%) 27 (6.6%)
35-44 4517 (17.6%) 81 (12.1%) 54 (12.1%) 45 (12.1%) 109 (15.4%) 112 (13.2%) 47 (9.9%) 70 (12.1%) 42 (9.9%) 47 (11.0%)
45-54 3865 (14.3%) 90 (13.2%) 51 (12.1%) 52 (14.3%) 105 (15.4%) 114 (14.3%) 53 (11.0%) 81 (14.3%) 57 (14.3%) 66 (15.4%)
55-64 3332 (13.2%) 142 (20.9%) 87 (19.8%) 72 (18.7%) 111 (15.4%) 140 (16.5%) 93 (19.8%) 105 (18.7%) 77 (18.7%) 79 (18.7%)
65-74 2162 (7.7%) 102 (14.3%) 89 (20.9%) 73 (19.8%) 102 (14.3%) 133 (16.5%) 106 (22.0%) 101 (18.7%) 74 (18.7%) 100 (23.1%)
75-84 1416 (5.5%) 75 (11.0%) 63 (14.3%) 61 (16.5%) 65 (8.8%) 77 (8.8%) 79 (16.5%) 70 (12.1%) 56 (14.3%) 65 (15.4%)
85 + 706 (2.2%) 32 (4.4%) 30 (6.6%) 30 (7.7%) 25 (3.3%) 42 (5.5%) 46 (9.9%) 41 (7.7%) 29 (7.7%) 23 (5.5%)
Gender
Female 16013 (60.5%) 405 (58.3%) 278 (63.8%) 240 (63.8%) 430 (61.6%) 538 (64.9%) 317 (66.0%) 346 (62.7%) 254 (62.7%) 276 (63.8%) 0.252
Male 10274 (39.6%) 285 (41.8%) 155 (36.3%) 138 (36.3%) 267 (38.5%) 286 (35.2%) 165 (34.1%) 209 (37.4%) 151 (37.4%) 153 (35.2%)
Emergency Severity Index
Unknown 3327 (13.2%) 85 (12.1%) 71 (16.5%) 64 (16.5%) 88 (12.1%) 104 (12.1%) 81 (16.5%) 70 (12.1%) 59 (14.3%) 79 (18.7%) 0.514
High urgency 2956 (11.0%) 91 (13.2%) 71 (16.5%) 50 (13.2%) 103 (14.3%) 117 (14.3%) 62 (13.2%) 89 (16.5%) 56 (14.3%) 53 (12.1%)
Medium urgency 12209 (46.2%) 326 (47.3%) 179 (41.8%) 179 (47.3%) 327 (47.3%) 395 (48.4%) 229 (47.3%) 275 (49.5%) 199 (49.5%) 205 (47.3%)
Low urgency 7795 (29.7%) 188 (27.5%) 112 (26.4%) 85 (22.0%) 179 (25.3%) 208 (25.3%) 110 (23.1%) 121 (22.0%) 91 (22.0%) 92 (20.9%)
Primary diagnosis
Unknown 3970 (15.4%) 106 (15.4%) 62 (14.3%) 66 (17.6%) 104 (15.4%) 149 (17.6%) 87 (17.6%) 103 (18.7%) 67 (16.5%) 66 (15.4%) 0.330
Infectious and parasitic diseases 410 (1.1%) 1 (<0.1%) 2 (<0.1%) 1 (<0.1%) 6 (1.1%) 11 (1.1%) 6 (1.1%) 4 (1.1%) 8 (2.2%) 6 (1.1%)
Neoplasms 51 (<0.1%) 0 (0.0%) 2 (<0.1%) 0 (0.0%) 0 (0.0%) 1 (<0.1%) 1 (<0.1%) 0 (0.0%) 2 (<0.1%) 1 (<0.1%)
Endocrine; nutritional and metabolic diseases and immunity disorders 414 (1.1%) 16 (2.2%) 12 (3.3%) 5 (1.1%) 11 (1.1%) 16 (2.2%) 12 (2.2%) 9 (1.1%) 6 (1.1%) 7 (1.1%)
Diseases of the blood and blood-forming organs 73 (<0.1%) 2 (<0.1%) 1 (<0.1%) 3 (1.1%) 1 (<0.1%) 5 (1.1%) 2 (<0.1%) 5 (1.1%) 1 (<0.1%) 1 (<0.1%)
Mental Illness 127 (<0.1%) 2 (<0.1%) 1 (<0.1%) 1 (<0.1%) 0 (0.0%) 3 (<0.1%) 1 (<0.1%) 1 (<0.1%)
Diseases of the nervous system and sense organs 1928 (7.7%) 50 (7.7%) 30 (6.6%) 27 (6.6%) 49 (6.6%) 56 (6.6%) 31 (6.6%) 48 (8.8%) 37 (8.8%) 37 (8.8%)
Diseases of the circulatory system 2052 (7.7%) 69 (9.9%) 47 (11.0%) 40 (11.0%) 74 (11.0%) 82 (9.9%) 62 (13.2%) 54 (9.9%) 48 (12.1%) 56 (13.2%)
Diseases of the respiratory system 3060 (12.1%) 79 (11.0%) 66 (15.4%) 35 (8.8%) 76 (11.0%) 88 (11.0%) 53 (11.0%) 51 (8.8%) 50 (12.1%) 38 (8.8%)
Diseases of the digestive system 1575 (5.5%) 40 (5.5%) 21 (4.4%) 19 (5.5%) 45 (6.6%) 45 (5.5%) 30 (6.6%) 35 (6.6%) 23 (5.5%) 20 (4.4%)
Diseases of the genitourinary system 1618 (6.6%) 52 (7.7%) 24 (5.5%) 26 (6.6%) 47 (6.6%) 53 (6.6%) 22 (4.4%) 39 (6.6%) 28 (6.6%) 18 (4.4%)
Complications of pregnancy; childbirth and the puerperium 1307 (5.5%) 19 (3.3%) 11 (2.2%) 5 (1.1%) 27 (4.4%) 32 (4.4%) 10 (2.2%) 13 (2.2%) 12 (3.3%) 11 (2.2%)
Diseases of the skin and subcutaneous tissue 701 (2.2%) 19 (3.3%) 8 (2.2%) 10 (2.2%) 21 (3.3%) 14 (2.2%) 7 (1.1%) 12 (2.2%) 13 (3.3%) 6 (1.1%)
Diseases of the musculoskeletal system and connective tissue 1996 (7.7%) 47 (6.6%) 28 (6.6%) 31 (7.7%) 63 (8.8%) 62 (7.7%) 27 (5.5%) 46 (8.8%) 22 (5.5%) 37 (8.8%)
Congenital anomalies 5 (<0.1%) 0 (0.0%) 0 (0.0%) 0 (0.0%) 0 (0.0%) 0 (0.0%) 1 (<0.1%) 0 (0.0%) 0 (0.0%) 0 (0.0%)
Injury and poisoning 4061 (15.4%) 111 (16.5%) 69 (15.4%) 71 (18.7%) 113 (16.5%) 118 (14.3%) 79 (16.5%) 77 (14.3%) 60 (14.3%) 79 (18.7%)
Symptoms signs and ill-defined conditions and factors influencing health 2608 (9.9%) 68 (9.9%) 44 (9.9%) 32 (8.8%) 55 (7.7%) 83 (9.9%) 47 (9.9%) 55 (9.9%) 26 (6.6%) 43 (9.9%)
Residual codes; unclassified 331 (1.1%) 9 (1.1%) 5 (1.1%) 6 (1.1%) 5 (1.1%) 6 (1.1%) 4 (1.1%) 3 (<0.1%) 2 (<0.1%) 3 (1.1%)
Self-reported general health
Unknown -- 21 (3.3%) 10 (2.2%) 2 (<0.1%) 16 (2.2%) 18 (2.2%) 9 (2.2%) 10 (2.2%) 13 (3.3%) 8 (2.2%) 0.021
Poor -- 45 (6.6%) 24 (5.5%) 16 (4.4%) 51 (7.7%) 59 (7.7%) 26 (5.5%) 19 (3.3%) 27 (6.6%) 27 (6.6%)
Fair -- 152 (22.0%) 81 (18.7%) 73 (19.8%) 160 (23.1%) 197 (24.2%) 114 (24.2%) 108 (19.8%) 77 (18.7%) 101 (23.1%)
Good -- 210 (30.8%) 141 (33.0%) 124 (33.0%) 223 (31.9%) 234 (28.6%) 133 (27.5%) 198 (35.2%) 122 (29.7%) 149 (35.2%)
Very Good -- 178 (25.3%) 126 (28.6%) 116 (30.8%) 157 (22.0%) 214 (26.4%) 149 (30.8%) 148 (26.4%) 120 (29.7%) 96 (22.0%)
Excellent -- 84 (12.1%) 51 (12.1%) 47 (12.1%) 90 (13.2%) 102 (12.1%) 51 (11.0%) 72 (13.2%) 46 (11.0%) 48 (11.0%)
Self-reported mental health
Unknown -- 21 (3.3%) 11 (2.2%) 1 (<0.1%) 18 (2.2%) 19 (2.2%) 10 (2.2%) 8 (1.1%) 15 (3.3%) 10 (2.2%) 0.008
Poor -- 22 (3.3%) 20 (4.4%) 11 (3.3%) 35 (5.5%) 25 (3.3%) 18 (3.3%) 12 (2.2%) 17 (4.4%) 9 (2.2%)
Fair -- 91 (13.2%) 45 (9.9%) 32 (8.8%) 93 (13.2%) 108 (13.2%) 51 (11.0%) 63 (11.0%) 43 (11.0%) 45 (11.0%)
Good -- 175 (25.3%) 105 (24.2%) 75 (19.8%) 166 (24.2%) 213 (25.3%) 97 (19.8%) 143 (25.3%) 76 (18.7%) 112 (26.4%)
Very Good -- 198 (28.6%) 136 (31.9%) 143 (37.4%) 187 (26.4%) 237 (28.6%) 169 (35.2%) 169 (30.8%) 129 (31.9%) 129 (29.7%)
Excellent -- 183 (26.4%) 116 (26.4%) 116 (30.8%) 198 (28.6%) 222 (26.4%) 137 (28.6%) 160 (28.6%) 125 (30.8%) 124 (28.6%)
Self-reported Education
Unknown -- 21 (3.3%) 13 (3.3%) 3 (1.1%) 22 (3.3%) 26 (3.3%) 13 (2.2%) 12 (2.2%) 13 (3.3%) 9 (2.2%) 0.116
8th grade or less -- 17 (2.2%) 13 (3.3%) 8 (2.2%) 20 (3.3%) 18 (2.2%) 19 (4.4%) 18 (3.3%) 13 (3.3%) 16 (3.3%)
Some high school -- 65 (9.9%) 40 (8.8%) 17 (4.4%) 59 (8.8%) 55 (6.6%) 24 (5.5%) 36 (6.6%) 24 (5.5%) 30 (6.6%)
High School or GED -- 186 (27.5%) 99 (23.1%) 91 (24.2%) 177 (25.3%) 225 (27.5%) 125 (26.4%) 126 (23.1%) 98 (24.2%) 110 (25.3%)
Some college or 2-year degree -- 217 (31.9%) 138 (31.9%) 143 (37.4%) 243 (35.2%) 292 (35.2%) 160 (33.0%) 188 (34.1%) 130 (31.9%) 141 (33.0%)
4-year college graduate -- 93 (13.2%) 65 (15.4%) 62 (16.5%) 86 (12.1%) 89 (11.0%) 61 (13.2%) 91 (16.5%) 66 (16.5%) 61 (14.3%)
More than 4-year college degree -- 91 (13.2%) 65 (15.4%) 54 (14.3%) 90 (13.2%) 119 (14.3%) 80 (16.5%) 84 (15.4%) 61 (15.4%) 62 (14.3%)
Self-reported race/ethnicity
Unknown -- 38 (5.5%) 14 (3.3%) 4 (1.1%) 36 (5.5%) 33 (4.4%) 18 (3.3%) 18 (3.3%) 23 (5.5%) 16 (3.3%) <0.001
Hispanic -- 68 (9.9%) 32 (7.7%) 26 (6.6%) 83 (12.1%) 91 (11.0%) 42 (8.8%) 51 (8.8%) 32 (7.7%) 32 (7.7%)
Native American -- 7 (1.1%) 4 (1.1%) 1 (<0.1%) 7 (1.1%) 9 (1.1%) 4 (1.1%) 4 (1.1%) 2 (<0.1%) 4 (1.1%)
Black -- 91 (13.2%) 48 (11.0%) 30 (7.7%) 92 (13.2%) 124 (15.4%) 35 (7.7%) 54 (9.9%) 31 (7.7%) 43 (9.9%)
Asian or Pacific Islander -- 15 (2.2%) 9 (2.2%) 9 (2.2%) 7 (1.1%) 23 (3.3%) 14 (3.3%) 17 (3.3%) 15 (3.3%) 10 (2.2%)
White -- 431 (62.7%) 320 (73.7%) 301 (79.2%) 419 (60.5%) 499 (60.5%) 365 (75.9%) 398 (71.5%) 291 (71.5%) 318 (73.7%)
Multiracial -- 40 (5.5%) 6 (1.1%) 7 (2.2%) 53 (7.7%) 45 (5.5%) 4 (1.1%) 13 (2.2%) 11 (2.2%) 6 (1.1%)