Impact of ITP on physician visits and workplace productivity

Abstract

Objective:

To assess the impact of immune thrombocytopenic purpura (ITP) on primary care and specialist visits and workplace productivity.

Research design and methods:

This was a cross-sectional, descriptive study comparing ITP patients to age- and gender-matched controls. Subjects completed a one-time web-based survey, which included questions on work loss, work productivity, and physician visits. ITP patients and controls were compared on these outcomes. For ITP patients, the relationship between work-related issues and physician visits with clinical characteristics (time since diagnosis, platelet count, number of treatments received, and an ITP-specific health-related quality of life measure, the ITP-PAQ) was explored.

Results:

A total of 1002 ITP patients and 1031 controls completed the survey. On average, ITP patients were 46 years old, diagnosed 9 years ago, and had platelet counts of 148 × 10⁹/L; 37% had undergone splenectomy. More ITP patients had primary care (20% vs. 11%) and specialist (28% vs. 11%) visits in the past month versus controls (p ≤ 0.001). Higher proportions of ITP patients have ever taken sick leave (56% vs. 30%), and missed chore hours in the past week (18% vs. 13%) (p ≤ 0.003). ITP patients scored significantly worse than controls on all six work productivity items. Patients diagnosed within the past year were more likely to have specialist visits and to miss chore hours versus those diagnosed less recently. Worse ITP-PAQ scores and more ITP-related treatments were related to more physician visits and worse work-related and productivity outcomes. Platelet count is not associated with these outcomes. The study is limited by the potential for biased samples due to recruitment approaches, the inherent issues of a cross-sectional study design and recall bias in questionnaire responses.

Conclusions:

ITP was consistently associated with more physician visits and worse work and productivity outcomes. Future research should build on these findings by calculating a comprehensive cost-of-illness of ITP including both direct and indirect costs.

Key words::

• Burden of illness
• Immune thrombocytopenic purpura
• Physician visits
• Survey
• Work loss
• Work productivity

Transparency

Declaration of funding

This research was funded by Amgen Inc., Thousand Oaks, CA, USA in part through a contract to Health Outcomes Solutions. The Platelet Disorder Support Association received funding from Amgen for their participation in the project, including reviewing the survey and identifying potential participants.

Declaration of financial/other relationships

S.D.M. and C.F.S. have disclosed that their contribution to this publication was as paid consultants. M.T., T.G. and J.Y. have disclosed that they serve as advisors to Amgen Inc. J.J.I. has disclosed that he is employed by Amgen.

Some peer reviewers receive honoraria from CMRO for their review work. The peer reviewers of this paper have disclosed that they have no relevant financial relationships.

Acknowledgment

The authors acknowledge the contributions of Jason Legg, Amgen, in conducting the analyses and Ross Crosby, Health Outcomes Solutions, for his statistical guidance. They also thank Betsy Tschosik, Health Outcomes Solutions, for assistance in the preparation of this manuscript and Michelle Zakson, Amgen, for technical assistance.

The analyses were conducted by Amgen. The online survey was conceived, programmed and hosted in conjunction with Harris Interactive. The manuscript was subject to Amgen review prior to submission. However, M.T. maintained final control over content.