Table 2.
The impact of covariates on the rate of program adoption (Prentice, Williams, and Peterson Gap–Time model estimation resultsa,b).
Variables | Program adoption through website | Mobile app adoption | ||||
|
HRc,d (95% CI) | P value | HRd (95% CI) | P value | ||
NSESe quintile | ||||||
|
First | 1.000f | N/Ag | 1.000f | N/A | |
|
Second | 1.034 (1.015-1.054) | .002 | 0.940 (0.907-0.973) | .001 | |
|
Third | 1.029 (1.008-1.051) | .02 | 0.954 (0.918-0.990) | .02 | |
|
Fourth | 1.031 (1.009-1.053) | .02 | 0.950 (0.912-0.988) | .02 | |
|
Fifth | 1.020 (0.997-1.043) | .12 | 0.948 (0.910-0.987) | .02 | |
Age (in years) | 1.007 (1.006-1.007) | <.001 | 0.980 (0.979-0.981) | <.001 | ||
Gender | ||||||
|
Female | 1.000 | N/A | 1.000 | N/A | |
|
Male | 1.074 (1.060-1.088) | <.001 | 0.821 (0.797-0.845) | <.001 | |
Marketing | ||||||
|
No | 1.000 | N/A | 1.000 | N/A | |
|
Yes | 0.378 (0.360-0.396) | <.001 | 17.007 (16.979-17.035) | <.001 |
aInterpreting the estimated hazard ratios, for example, the second neighborhood socioeconomic status (NSES) quintile had an increased likelihood of program adoption via the website by a factor of 1.034 (95% CI 1.015-1.054) as compared with the lowest NSES quintile, keeping other covariates constant (equivalent to a 3.4% increased likelihood of adoption). On the other hand, the likelihood of adoption of the mobile app when comparing the second NSES quintile with the first one shows a decreased likelihood of adoption for the second NSES quintile by a factor of 0.940 (95% CI 0.907-0.973) or 6%.
bObservations=166,932 (the 166,932 observations reflect the 83,466 participants as the model accounts for 2 events per participant); R2=0.255; maximum possible R2=1.000; Wald test (df)=56,343.96 (14); P<.001.
cHR: hazard ratio.
dAn HR of 1.000 was assigned to the reference level for each categorical covariate.
eNSES: neighborhood socioeconomic status.
fFor the HR of 1.000 there is no 95% CI reported, as this is not an estimated HR, but is the default value assigned to the reference level.
gN/A: not applicable (it is the reference level).