Erik Taal

Productivity loss due to absenteeism and presenteeism by different instruments in patients with RA and subjects without RA

OBJECTIVESnTo explore the impact of at-work productivity loss on the total productivity cost by different instruments in patients recently diagnosed with RA and controls without RA.nnnMETHODSnCross-sectional data were collected from outpatients with RA between December 2007 and February 2008. The control group was formed by subjects without RA matched on age and gender. Absenteeism and presenteeism were estimated by the Quantity and Quality (QQ) Questionnaire, Work Productivity and Activity Impairment Questionnaire General Health V2.0 (WPAI-GH) and Health and Labor Questionnaire (HLQ) questionnaires. Differences between groups were tested by Mann-Whitney U-test. Costs were valued by the human capital approach.nnnRESULTSnData were available from 62 patients with a paid job and 61 controls. QQ- and WPAI-GH scores of presenteeism were moderately correlated (ru2009=u20090.61) while the HLQ presenteeism score correlated poorly with the other instruments (ru2009=u20090.34). The contribution of presenteeism on total productivity costs was estimated at ∼70% in the RA group. The mean costs per person per week due to presenteeism varied between €79 and €318 per week in the RA group, dependent on the instrument used. The costs due to presenteeism were about two to four times higher in the RA group compared with the control group.nnnCONCLUSIONnThis study indicates that the impact of presenteeism on the total productivity costs in patients with RA is high. However, work productivity in individuals without RA was not optimal either, which implies a risk of overestimation of cost when a normal score is not taken into account. Finally, different presenteeism instruments lead to different results.

Comparison of measures of functional disability in patients with gout

OBJECTIVEnTo compare the measurement properties of the HAQ disability index (HAQ-DI), HAQ-II and short form 36 physical functioning scale (PF-10) in patients with gout.nnnMETHODSnA cross-sectional sample of 97 patients with gout completed all three measures. Reliability was assessed by examining the internal consistency of the scales. Validity was assessed by testing for expected intercorrelations and associations with other aspects of health status and the ability to discriminate between patients with different levels of general health. Additionally, distributional properties were examined.nnnRESULTSnAll three measures demonstrated high reliability (Cronbachs αu2009≥ 0.93), strong intercorrelations (ru2009 ≥u2009 0.75), and the expected pattern of external correlations. The HAQ-DI and HAQ-II performed somewhat better in discriminating between patients. However, both demonstrated ceiling effects of 34.0 and 25.8%, respectively, compared with only 7.2% of the patients scoring no disability on the PF-10.nnnCONCLUSIONSnThe HAQ-DI, HAQ-II and PF-10 demonstrated similar and adequate reliability and validity for measuring functional disability in patients with gout. The large ceiling effects of both HAQ versions, however, may point to limited content validity and responsiveness to change. Further research should examine whether current instruments cover all aspects of physical functioning relevant to patients with gout.

Worst-case future scenarios of patients with rheumatoid arthritis: a cross-sectional study

OBJECTIVEnThe time trade-off is a health-related quality of life instrument that measures valuations for health states (utilities) by asking patients to value their health state anchored on a scale between death (0) and perfect health (1). Dying earlier is not perceived as a realistic worst-case consequence of the disease by RA patients. Of the previous focus groups study on RA patients, five worst-case future scenarios emerged. The aim of this study was to examine which potential worst-case scenario was the most appropriate for RA patients to use in utility calculation.nnnMETHODSnIn a cross-sectional study of 74 consecutive RA patients visiting the rheumatology outpatient clinic, participants were presented with descriptions of the five worst-case future scenarios. In pairwise comparisons, patients had to choose the scenario that would be the worst to experience. The worst-case future scenario was defined by the scenario that was chosen by a significantly greater proportion of participants than could be expected based on chance (20%). Therefore, analysis based on a single fraction ( ) was used and 95% CI was calculated.nnnRESULTSnThe scenario being dependent on others was chosen most often as the worst to experience [by 35% of participants (95% CI 24%, 46%)] and significantly more often than could be expected based on chance ( u2009=u20090.35, zu2009=u20096.45, Pu2009=u20090.00).nnnCONCLUSIONnThe scenario being dependent on others is likely to be the most appropriate worst-case future scenario for RA patients. Using an alternative anchor could improve the validity and responsiveness of the time trade-off in RA patients.