Table 2.
Modeling the pattern of missing data by day of week (Models 1 and 2) and day of diary cycle (Models 3 and 4) using polynomial and trigonometric functions
| Term | Model 1: 7-day polynomial function |
Model 2: 7-day trigonometric function |
Model 3: 30-day polynomial function |
Model 4: 30-day trigonometric function |
||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| B | 95 %CI | p | B | 95 %CI | p | B | 95 %CI | p | B | 95 %CI | p | |
| Fixed effects | ||||||||||||
| Intercept | 1.63 | [1.46, 1.80] | <0.001 | 1.38 | [1.23, 1.54] | <0.001 | 1.85 | [1.61, 2.09] | <0.001 | 1.39 | [1.24, 1.55] | <0.001 |
| No college degree | –0.61 | [–0.93, –0.31] | <0.001 | –0.63 | [–0.94, –0.32] | <0.001 | –0.64 | [–0.95, –0.32] | <0.001 | –0.63 | [–0.95, –0.32] | <0.001 |
| Age | 0.04 | [0.02, 0.05] | <0.001 | 0.04 | [0.02, 0.05] | <0.001 | 0.04 | [0.02, 0.05] | <0.001 | 0.04 | [0.02, 0.05] | <0.001 |
| Heavy drinking days | –0.02 | [–0.04, 0.00] | 0.08 | –0.02 | [–0.04, 0.00] | 0.08 | –0.02 | [–0.04, 0.00] | 0.08 | –0.02 | [–0.04, 0.00] | 0.08 |
| Club drug use days | –0.06 | [–0.09, –0.03] | <0.001 | –0.06 | [–0.09, –0.03] | <0.001 | –0.06 | [–0.09, –0.03] | <0.001 | –0.06 | [–0.09, –0.03] | <0.001 |
| Linear | –0.28 | [–0.33, –0.23] | <0.001 | – | – | – | –0.03 | [–0.09, 0.02] | 0.25 | – | – | – |
| Quadratic | –0.08 | [–0.11, –0.05] | <0.001 | – | – | – | 0.00 | [0.00, 0.00] | 0.94 | – | – | – |
| Cubic | 0.03 | [0.03, 0.04] | <0.001 | – | – | – | 0.00 | [0.00, 0.00] | 0.83 | – | – | – |
| Sine | – | – | – | 0.40 | [0.33, 0.47] | <0.001 | – | – | – | 0.29 | [0.22, 0.36] | <0.001 |
| Cosine | – | – | – | –0.10 | [–0.16, –0.03] | 0.005 | – | – | – | 0.02 | [–0.05, 0.09] | 0.64 |
| Random effects | Est. | SE | Est. | SE | Est. | SE | Est. | SE | ||||
| Intercept | 1.88 | 0.17 | 1.89 | 1.17 | 1.93 | 0.18 | 1.92 | 0.18 | ||||
| AR(1) | 0.09 | 0.01 | 0.09 | 0.01 | 0.08 | 0.01 | 0.08 | 0.01 | ||||
| Residual | 0.85 | 0.01 | 0.85 | 0.01 | 0.86 | 0.01 | 0.86 | 0.01 | ||||
| –2 Residual LPL | 54829.18 | 54812.55 | 55310.46 | 55126.94 | ||||||||
Although not shown, models 3 and 4 were adjusted for the 7-day trigonometric effects identified in Model 2. The polynomial and trigonometric effects refer to those effects that are coded for the time frame named above each model (i.e., for the 7-day models, these are the weekly polynomial or trigonometric effects while for the 30-day models, these are day of cycle effects); the weekly effects within the 30-day models are not shown but were consistent in both magnitude and significance with those found in the 7-day models
AOR adjusted odds ratio, CI confidence interval, LPL log pseudo-likelihood