Pfizer Glucotrol XL Increases Workplace Productivity - JAMA Study

Pfizer's Glucotrol XL (glipizide GITS) cuts absenteeism rates in half, a short-term study of the oral antidiabetic therapy published in the Journal of the American Medical Association Nov. 4 concluded.

The 569-patient study found that 10.5% of placebo patients reported missing one half day or more of work after 15 weeks in the study, compared to 4.8% of placebo patients. "The absenteeism risk ratio (missed work cases per person-days worked) was 4.8... indicating a nearly 5-fold increase in risk of absenteeism for placebo vs. active therapy," the study says.

The study also found that after 15 weeks Glucotrol XL-treated patients were more likely to be employed (97% vs. 81%), worked more days each (5.1 days per person vs. 4.9), and spent fewer days in bed (5.5% reported at least half-a-day vs. 8.4% for placebo).

Using average daily wage estimates from census data, the study estimated production losses. Absenteeism increased losses by $91 per worker per month. Bed days caused $1,539 in losses for the Glucotrol group per 1,000 patient-days, compared to $1,843 for placebo. Restricted activity days cost $2,660 for the Glucotrol group compared to $4,275 for placebo.

The study was conducted by Marcia Testa, PhD, Harvard School of Public Health, and Donald Simonson, MD, Brigham and Women's Hospital, with funding provided by Pfizer, HHS' Agency for Health Care Policy & Research and the American Diabetes Association.

After a four-week wash-out period, patients were randomized to receive glipizide GITS or placebo plus diet management. The dose was titrated over four weeks to achieve fasting blood glucose levels of 6.4 mmol/L and patients stayed on therapy for another eight weeks.

In addition to lost work endpoints, the study assessed quality of life and the correlation between patient perceptions of illness and health outcomes. Glucotrol XL was shown to be significantly better in many of the QOL endpoints than placebo, and a correlation was seen between patient assessments and outcomes.

"Some investigators have postulated that QOL and glycemic control are unrelated and that patients do not perceive any short-term benefits with improved glycemic control, thereby leading to non-compliance with complex regimens," the authors observed. The study found, however, that "even a moderate worsening in HbA1c levels was shown to affect negatively the patient's QOL and overall well-being."

The short-term study design represented an attempt to supplement the existing database showing long-term benefits of tight blood glucose control both in terms of health and cost-effectiveness. "Although the direct and indirect costs of long-term diabetic complications have been established, there has been less attention on evaluating the health economic impact of changes in glycemic control and QOL on costs associated with work and absenteeism, functional restrictions in daily activities, and use of health care services."

The Pfizer study did find a slight difference in numbers of patients reporting ambulatory care visits and estimated a savings of $11 per patient per month from those data. There was no significant difference in hospitalization rates during the study.

The study is noteworthy both as an example of an attempt to assess cost-effectiveness using non-health-related costs and as evidence of Pfizer's interest in expanding its presence in the diabetes market.

There have been relatively few published cost-effectiveness studies measuring societal costs like lost work time. However, as pharmaceutical companies attempt to justify the increasing cost of prescription drugs, data that appeal directly to employers are likely to become more important.

"Patients, employers and health care providers might be more motivated to implement and comply with education and disease management programs if immediate QOL and health economic benefits could be anticipated," the article observes.

With $175 mil. in 1997 sales, Glucotrol XL is a relatively minor product for Pfizer and the conclusions of the study are likely to be extrapolated to competitors like Bristol-Myers Squibb's Glucophage and Warner-Lambert's Rezulin, as well as to generic immediate release glipizide.

However, the study does fit into Pfizer's plans to expand its presence in the diabetes market. The company is developing an inhaled insulin product which it is positioning for use by Type 2 diabetics (see preceding story).