Table 2 Final multivariate model showing patient characteristics in relation to message sending behaviour
Increased messaging rate (95% CI)Odds of having excess zeroes (95% CI)
VariableIRR (95% CI)OR (95% CI)
Generation
Youngest0.97 (0.82, 1.15)2.00 (1.38, 2.91)**
MillennialsReferenceReference
Generation X1.14 (1.04, 1.25)** 1.38 (1.06, 1.79)*
Baby Boomers1.25 (1.13, 1.38)*** 1.64 (1.24, 2.17)**
Silent and GI Generations1.50 (1.25, 1.81)*** 1.25 (0.72, 2.19)
Number of office visits
Lowest 3rd (1–2 visits)ReferenceReference
Middle 3rd (3–4 visits)1.02 (0.93, 1.13)1.11 (0.8, 1.54)
Top 3rd (5–161 visits)1.14 (1.03, 1.26)** 2.22 (1.64, 3.01)***
Number of messages received
Lowest 3rd (0–2 messages)ReferenceReference
Middle 3rd (3–7 messages)3.23 (2.74, 3.82)*** 0.18 (0.13, 0.26)***
Top 3rd (8–2589 messages)11.50 (9.72, 13.62)*** 0.08 (0.06, 0.12)***
Number of diagnoses
0ReferenceReference
11.18 (1.09, 1.28)** 1.38 (1.06, 1.77)*
2 or more1.20 (1.08, 1.32)** 1.92 (1.45, 2.54)***
White race
Yes1.17 (1.09, 1.27)*** 0.56 (0.42, 0.75)***
NoReferenceReference
English language preference
YesReference
No0.74 (0.61, 0.89)**
Gender
FemaleReference
Male0.88 (0.82, 0.95)**
Per cent people in ZIP code who graduated high school
Lowest 3rd0.88 (0.82, 0.96)**
(50.80%–69.40%)
Middle and top 3rdReference
(69.80%–83.10%)
Provider sends messages
YesReference
No0.85 (0.74, 0.99)*
Per cent people in ZIP code above poverty level
Lowest and Middle 3rdReference
(0%–28.30%)
Top 3rd (28.40%–42.90%)1.30 (1.06, 1.60)*
Insurance Type
PrivateReference
Public2.02 (1.61, 2.54)***
Uninsured2.03 (1.43, 2.90)***
Per cent of provider’s patients who use MyChart
Lowest 3rd (0%–30.43%)Reference
Middle 3rd0.60 (0.48, 0.75)***
(30.52%–38.62%)
Top 3rd (38.77%–75.00%)0.45 (0.34, 0.60)***
  • * Significant at level p = 0.05.

  • ** Significant at level p = 0.01.

  • *** Significant at level p < 0.0001.