Allergic disease therapies key to patient quality of life

March 1, 2005

Quality of life (QOL) has become an issue in every branch of medicine, including ophthalmology. From an economic perspective, loss of productivity contributes to the economic burden of a disease in the same manner as the shared costs of treatment.

The impact of QOL issues has begun to be quantified in cardiovascular disease, gastroenterology, geriatric medicine, and in all forms of allergic disease.1,2 Epidemiologic and statistical methodology and questionnaires-EQ-5D Health Questionnaire, Rhinoconjunctivitis Quality of Life Questionnaire [RQLQ], the National Eye Institute Visual Functioning Questionnaire 25 [VFQ-25], and the Allergic Conjunctivitis Quality of Life Questionnaire [ACQLQ], to name a few-have been developed to assess and compare QOL parameters affected by allergic disease.

QOL is expected to become a standard outcome measure in clinical trials, and is an important contribution to the patient-reported outcomes that compose the major part of allergic conjunctivitis study results.

In epidemiologic reports of allergy, many individuals with allergic conjunctivitis are often obscured within overall rhinitis statistics.

However, it has been established that allergic rhinoconjunctivitis (the combination of ocular and nasal allergies) affects at least 20% of the total population in industrialized countries, with slightly less expected in minimally or non-industrialized countries.3,4 These numbers are only a small percentage of the vast number of persons worldwide affected by allergy in all of its forms. Thus, allergy is a factor that has a great impact on society, influencing many QOL parameters.

One study revealed a direct association with depression and anxiety was reported in 19% of allergic outpatients, 46% who had never received psychopharmacotherapy, and whose condition, therefore, had never been diagnosed.5 Frequent mental distress was observed in 18.8% in adults with asthma.6

A second factor that intensifies the impact of allergy is the target age of the population, which coincides with the average age of the work force and the most productive period of an individual's life.

Pharmacoeconomic studies abound in relation to allergy and asthma. In one report, direct and indirect expenditures were estimated at $6 billion (based on 1996 dollars).7 Expenditures related to ocular allergy prescriptions have risen from $6 million in the 1990s to more than $300 million in the new millennium. Japanese clinical studies have started to introduce the Work Productivity and Activity Impairment-Allergy Specific Questionnaire to assess work productivity in patients with allergy.8 Productivity losses related to absenteeism associated with a diagnosis of allergic rhinitis in 1995 were estimated to be $601 million.

Yet, when workers' self-assessments of in-work productivity were added to this figure, productivity losses ranged from $2.4 to 4.6 billion.9 Interestingly, in one study, decreased job effectiveness was more frequently reported with rhinoconjunctivitis than with asthma.10 Finally, a significant correlation was found between an increase in pollen counts and a decrease in worker productivity in workers with allergies.11

Finding better treatments The constant effort to improve the treatment of ocular allergy and minimize its effect on QOL can be seen in the selection of ever more effective anti-allergic agents available. These agents strive to prevent or immediately alleviate the signs and symptoms of ocular allergy in the lowest of daily dosages, with the most comfortable formulation. It is becoming more common to investigate not only physician-reported outcomes, but also QOL parameters as well as the comparative cost effectiveness of compounds for the treatment of allergic conjunctivitis.

New models for evaluating the QOL and economic characteristics of ocular allergy therapy should continue to improve the choices available as well as improving our ability to compare these drugs' relative performance in terms of patient's QOL. Recognition of the importance of formulation comfort is critical in that this relates directly to QOL: patients do not want to suffer to feel better. Similarly, a prolonged duration of action means less frequent instillation and greater compliance-another parameter that directly influences the impact of ocular allergy on the patient's QOL.