Table 5 Mixed-effects negative binomial regression estimates of between-person and within-person changes in computer time associated with changes in parental status and employment status over 5 years (2007/08–2011/13)

Model 1

Model 2

% of

Model 3

% of chaChange

IRR (95% CI)

IRR (95% CI)

change

IRR (95% CI)

change

  Never had children

Ref

  Living with children under 18 during study

0.75 (0.67, 0.85)***

0.84 (0.75, 0.96)*

12%

0.91 (0.80, 1.03)

8.3%

 Remain with no children

Ref

 Number of children remain unchanged

0.74 (0.64, 0.84)***

0.78 (0.69, 0.90)**

5.4%

0.78 (0.67, 0.90)**

  0%

 First child/ Additional children

0.77 (0.66, 0.90)**

0.77 (0.66, 0.90)**

0%

0.75 (0.64 0.88)**

−2.6%

 Fewer children < 18 yrs. living at home

0.76 (0.64, 0.91)**

0.83 (0.69, 1.01)

9.2%

0.80 (0.66, 0.97)*

−3.6%

  Employed full-time during the study period

Ref

  Not employed full-time during the study period

0.70 (0.66, 0.75)***

0.73 (0.68, 0.78)***

4.3%

0.79 (0.73, 0.85)***

8.2%

  Remain full-time

Ref

  Remain part-time/not working

0.81 (0.74, 0.88)***

0.82 (0.75, 0.90)***

1.2%

0.76 (0.68, 0.84)***

−7.3%

  Increased working hours

0.87 (0.80, 0.95)**

0.89 (0.81, 0.98)**

2.3%

0.88 (0.80, 0.97)*

−1.2%

  Reduced working hours

0.66 (0.59, 0.75)***

0.67 (0.60, 0.75)***

1.5%

0.67 (0.59, 0.75)***

  0%