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. Author manuscript; available in PMC: 2013 Feb 1.
Published in final edited form as: J Occup Environ Med. 2012 Feb;54(2):128–135. doi: 10.1097/JOM.0b013e31824409d8

Table 3.

Post-Intervention Comparison of the Work and Health Initiative (WHI) Treatment Group and Usual Care Group

WHI Treatment Usual Care (N=27) Difference Between Change Scores
Baseline (N=52) Follow-up (N=47) Change Baseline (N=27) Follow-up (N=25) Change





Mean SD Mean SD Mean Effect Size DF Mean SD Mean SD Mean Effect Size DF Δ Effect Size P-Value DF
WLQ Scores
Time Management 45.6 20.8 27.5 19.0 −18.1 −0.87 1,49 43.7 17.6 42.7 16.5 −0.9 −0.05 1,26 −15.4 −0.73 0.005 1,62
Physical Tasks 23.3 21.2 12.4 15.4 −10.9 −0.51 1,49 18.3 22.1 16.2 17.6 −2.0 −0.09 1,26 −11.7 −0.54 0.027 1,64
Mental-Interpersonal Tasks 37.3 15.8 25.5 17.0 −11.8 −0.75 1,50 38.5 14.6 36.8 16.4 −1.6 −0.11 1,26 −9.5 −0.59 0.017 1,64
Output Tasks 40.7 23.2 26.5 23.5 −14.2 −0.61 1,51 39.1 22.8 40.1 22.1 1.0 0.04 1,26 −13.9 −0.70 0.006 1,64
% At-Work Productivity Loss 10.3 4.3 6.8 4.3 −3.5 −0.81 1,48 10.1 3.8 9.8 4.0 −0.3 −0.08 1,26 −2.9 −0.78 0.002 1,61
Absences
Days Missed Per Two Weeks 1.7 1.7 1.0 1.2 −0.8 −0.47 1,50 1.1 1.4 2.2 2.6 1.1 0.79 1,26 −1.7 −0.87 0.001 1,65
% Productivity Loss due to Absence 16.6 14.6 9.5 12.1 −7.1 −0.49 1,50 11.9 14.2 20.9 23.8 9.0 0.63 1,26 −15.0 −0.90 0.001 1,61
PHQ-9 Symptom Severity 13.1 5.1 7.7 5.8 −5.4 −1.06 1,51 12.2 5.6 12.8 6.4 0.6 0.11 1,26 −6.8 −1.09 0.001 1,66

DF = degrees of freedom

Statistically significant change scores and change differences at the P≤.05 level are indicated in bold

The effect sizes for the difference between the change scores were calculated by dividing the change difference by the pooled standard deviations of the change scores for both the Usual Care and the treatment group change.

The difference between change scores between groups were adjusted by baseline score, age, gender and types of occupation (white collar vs. blue collar)