Table 2.
Results of negative binomial models testing the effects of email body on number of clicks on the fact sheet.
| N | Fact Sheet Clicks (ŷ) | % Clicks |
IRR (95 % CI) |
SE | z | p | |
|---|---|---|---|---|---|---|---|
| Trial 1: Challenges faced by parents with addiction | 5964 | 454 (0.08) | 4.2 | ||||
| Control (ref); Narrative & fact sheet author sender | 2974 | 192 (0.06) | 3.4 | - | - | - | - |
| Personal narrative with lived experience; Narrative & fact sheet author sender | 2991 | 262 (0.09) | 5.0 |
1.37 (1.00, 1.87) |
0.22 | 1.97 | .049 |
| Trial 2: Substance use research for [legislator name] | 9496 | 1298 (0.14) | 7.8 | ||||
| Control (ref); Narrative & fact sheet author sender | 3190 | 384 (0.12) | 7.3 | - | - | - | - |
| Research narrative with lived experience; Narrative & fact sheet author sender | 3134 | 414 (0.13) | 7.5 | 1.07 (0.86, 1.34) |
0.12 | 0.64 | .523 |
| Research narrative with no lived experience; Narrative & fact sheet author sender | 3172 | 500 (0.16) | 8.4 |
1.32 (1.06, 1.64) |
0.15 | 2.51 | .012 |
| Trial 3: Fach sheet on interventions for substance use disorders | 11,099 | 857 (.08) | |||||
| Control (ref); Fact sheet editor sender | 3703 | 601 (.16) | 16.2 | - | - | - | - |
| Third-person narrative; Fact sheet editor sender | 3699 | 140 (.04) | 3.8 |
0.23 (0.19, 0.29) |
0.03 | −12.83 | <.001 |
| First-person narrative; Fact sheet editor sender | 3697 | 116 (.03) | 3.1 |
0.19 (0.15, 0.24) |
0.02 | −13.71 | <.001 |
| Trial 4: Resource on substance use helplines and peer support | 11,212 | 821 (.07) | |||||
| Control (ref); Fact sheet author sender | 3729 | 479 (.13) | 12.8 | - | - | - | - |
| Long third-person; Fact sheet author sender | 3747 | 168 (.04) | 4.5 |
0.35 (0.27, 0.45) |
0.05 | −8.00 | <.001 |
| Short third-person; Fact sheet author sender | 3736 | 174 (.05) | 4.7 |
0.36 (0.28, 0.47) |
0.05 | −7.76 | <.001 |
| Trial 5: Research on prescription opioid labels | 10,604 | 502 (.05) | |||||
| Control (ref); Fact sheet author sender | 3533 | 164 (.05) | 4.6 | - | - | - | - |
| Third-person; Fact sheet author sender | 3534 | 143 (.04) | 4.0 | 0.87 (0.64, 1.19) |
0.14 | −0.86 | .388 |
| First-person; Narrative author sender | 3537 | 195 (.06) | 5.5 | 1.19 (0.88, 1.60) |
0.18 | 1.12 | .261 |
Note. ŷ = predicted value of clicks (the mean); IRR = incident ratio interval; CI = confidence interval; SE = standard error. % clicks represents the percentage of recipients who clicked the link, while the raw number of clicks is the total number of clicks across all recipients.