Stanford Presenteeism Scale-13

Workers/General Population: (Turpin et al, 2004; n = 7,797)

• Significant main effect for sex (p < 0.05) and WIS: Men (20.6) reporting marginally less impaired presenteeism than women (21.3).
• Significant main effect for age and WIS (p < 0.05) showcasing a trend for less impaired presenteeism being reported as employee’s age increases (WIS scores ranged from 22.2 at less than 25 years of age, to 19.8 at age 56 and older.)
• Significant difference between the WIS reported for persons with arthritis/joint pain in knowledge-based jobs (18.67) and persons with arthritis/joint pain in production-based jobs (22.48; t = 3.175; p < 0.002). The magnitude of the difference was fairly large (about 20%).
  • Large, but statistically insignificant differences were observed for other primary health conditions such as asthma, most likely due to small cell sizes.

Employees at Two Enterprises: (Yamashita & Arakida, 2008, First survey to 359 female employees in enterprise A with inclusion criteria of presence of some health conditions and answers to all 10 items on the WIS; age groups from 20-29 to 50+; 187 (52.1%) full-time; job type = clerks (51.0%), production-based workers (39.4%), technicians (3.1%), and others (6.5%). Second test-retest survey to 50 female employees (33 responses) with inclusion criteria the presence of some health conditions at both time points, mean age = 40.6 (9.8), 80% were occupational health staff. Japanese sample.)

Mean scores of WIS, WOS, and hours of sickness absenteeism (n = 359)

Component/factor

Mean (SD)

Work impairment score

30.8 (17.1)

Work output score

80.2 (13.1)

Sickness absenteeism (hours)

5.2 (9.9)

Work impairment scores by age, all subjects

Age Group (yr)/Total

n (%)

Mean (SD)

<=29

56 (15.6)

33.1 (17.8)

30-39

90 (25.1)

35.0 (17.1)

40-49

89 (24.8)

31.4 (15.8)

>=50

124 (34.5)

26.2 (17.0)

Total

359 (100.0)

30.8 (17.1)

F = 5.3, p < 0.01

Work impairment scores by age, full-time workers

Age Group (yr)/Total

n (%)

Mean (SD)

<=29

55 (98.2)

33.1 (17.8)

30-39

79 (87.8)

34.5 (16.7)

40-49

44 (49.4)

35.2 (16.7)

>=50

9 (7.3)

25.6 (20.5)

Total

187 (52.1)

33.8 (17.1)

F = 0.85, p > 0.05

Work impairment scores by age, part-time workers*

Age Group (yr)/Total

n (%)

Mean (SD)

<=29

1 (1.8)

35

30-39

11 (12.2)

38.2 (20.4)

40-49

45 (50.6)

27.8 (13.9)

>=50

115 (92.7)

26.2 (16.8)

Total

172 (47.9)

27.4 (16.5)

F = 2.71, p > 0.05

*ANOVA among part-time workers performed by excluding a subject less than 30 years old.

Employees at Two Enterprises: (Yamashita & Arakida, 2008, n = 33, Japanese sample)

• Acceptable test-retest reliability for the WIS: (ICC = 0.86; r = 0.83, p < 0.001)
• Acceptable test-retest reliability for the Work Output Score (WOS): (ICC = 0.91; r = 0.789, p < 0.001)  

Workers/General population: (Turpin et al., 2004); n = 7,797)

• Excellent: Cronbach's alpha coefficient for the WIS was 0.82*.

*Reliability improved marginally to 0.83 in overall population and types of job when an item was removed (“were you unable to take satisfaction in your work”).

Employees at Two Enterprises: (Yamashita & Arakida, 2008, n = 359, Japanese sample)

• Excellent: Cronbach's alpha of WIS was 0.87
• Excellent: Cronbach's alpha of WIS in full-time workers was 0.88
• Excellent: Cronbach's alpha of WIS in part-time workers was 0.85

Predictive validity:

Workers/General Population: (Turpin et al, 2004; n = 7,797)

• Poor predictive validity between health care use/expenditures and absenteeism or presenteeism metrics (r < 0.10 for all)
• Significant and robust positive relationship between the WIS and number of hours of absenteeism self-reported on the SPS
• Correlations between administrative-report payroll absenteeism and WIS were not significant 

Concurrent validity:

Workers/General Population: (Turpin et al, 2004; n = 7,797)

• Adequate concurrent validity between WIS and the Work Limitations Questionnaire (WLQ) Overall Index (r = 0.50)
• Poor to adequate concurrent validity between WIS and the four subscales of the WLQ: output demands scale (r = 0.49), mental/ interpersonal demands (r = 0.41), physical demands (r = 0.37), and time management (r = 0.20). 

Construct Validity:

Workers/General Population: (Turpin et al., 2004); n = 7,797)

• SPS appeared to be valid for both knowledge- and production-based jobs, yet there are important differences between them. The first factor of WIS for knowledge-based jobs (Completing Work) accounted for 93% of the variance in WIS scores, while the second factor of WIS (Avoiding Distraction) accounted 95% of variance in WIS scores in production-based jobs. Thus, all ten items of WIS are essential to assess and account for impairments in presenteeism.

Employees at Two Enterprises: (Yamashita & Arakida, 2008, n = 359, Japanese sample)

• Factorial analysis of the WIS data identified two factors: “completing work” and “avoiding distraction.”
  • These two factors accounted for a cumulative 50.8% of the variance—49.9% for full-time workers and 51.9% for part-time workers

Convergent Validity:

Workers/General population: (Turpin et al., 2004); n = 7,797)

• Convergent validity was assessed through the comparison of the WIS and WOS with health status
• WIS was significantly correlated to all eight SF-36 subscales: physical functioning (r = -0.25), role limitations-physical (r = -0.35), pain (r = -0.33), general health (r = -0.45), vitality (r = -0.61), social functioning (r = -0.56), role limitations-emotional (r = -0.51), and general mental health (r = -0.62)
  • Some differences between production- and knowledge-based jobs on the above correlations, but the trends are similar.
• WLQ had lower correlations with the SF-36 subscores in comparison to the SPS (total population range: 0.31-0.44; knowledge-based jobs range = 0.15 to 0.40, higher correlations on mental health questions; production-based jobs range = 0.29 to 0.56

Employees at Two Enterprises: (Yamashita & Arakida, 2008, n = 359, Japanese sample)

• Poor to Adequate convergent validity between the Work Impairment Score (WIS) and The Medical Outcomes Study 36-item Short Form Health Survey (SF-36)

Pearson’s correlation coefficients between WIS and SF-36 subscores

SF-36 subscores

r

Physical functioning

-0.13a

Role-physical

-0.37b

Bodily pain

-0.32b

Social functioning

-0.38b

General health perceptions

-0.38b

Vitality

-0.46b

Role-emotional

-0.46b

Mental Health

-0.43b

ap < 0.05 (Poor), bp < 0.01 (Adequate)

• Excellent convergent validity between WIS and WOS (r = -0.66**)
• Poor convergent validity between WIS and Job Content Questionnaire subscores for demand (r = 0.13*), support (r = 0.22**), and daily hassles (r = 0.29**)
• Adequate negative correlations between WIS and job satisfaction (r = -0.39**) 

*p < 0.05, **p < 0.01

Musculoskeletal Conditions: (Roy et al., 2011)

• Excellent: Cronbach’s alpha ranged between 0.82 and 0.87 for the Work Impaired Score (WIS) subscale.

Convergent validity:

Musculoskeletal Conditions: (Roy et al., 2011)

• Low to moderate correlations between SPS-13, WLQ-25, and SF-36 were observed.
• Adequate to excellent correlations were obtained between the presenteeism scales of EWPS, SPS-13, AND WLQ-25 (r = 0.55 to 0.69) 

“It was concluded that the instrument presented acceptable validity content, but WIS score should be interpreted carefully. WIS score demonstrated significant differences across sex and age, with men claiming slightly less impaired presenteeism and a trend for less reported impaired presenteeism with increasing age of employees.” (Roy et al., 2011)