Medical adherence is defined as “the extent to which a person’s behaviour (in terms of taking medications, following a diet, or modifying habits or attending clinics) coincides with medical or health advice,” Adherence remains a problem among all chronic respiratory diseases, with rates averaging approximately 50% having been reported for asthma , COPD, and obstructive sleep apnea. The adherence rate of 50% means that, on average, a single patient only takes his/her medication correctly half of the time, or half of the patient population uses their therapy correctly. Whatever the investigator’s definition of correct adherence is, it is in general agreement that a large proportion of patients do not adhere to their prescribed regimen. Poor adherence leads to increased morbidity and mortality, increased hospitalizations, a decrease in quality of life, and even death. The costs of poor adherence to medication regimens have been estimated to be as high as $100 billion annually. Specifically for LTOT, adherence rates have been estimated to be in the range of about 40-75%.
The criteria to determine the percentage of patients correctly using the therapy was oxygen use for an average of >15 hours per day. This lack of adherence is associated with the same consequences of non-adherence across all chronic therapies, in terms of both patient health and healthcare costs. Failure to adhere to correct oxygen use can lead to increased hospitalizations, increased morbidity and mortality, and decreased the quality of life. COPD causes more than 500,000 hospitalizations and more than 100,000 deaths each year in the United States. The liquid oxygen system is the most convenient portable system; however, it is the most expensive. The most common and economical method is to use the oxygen concentrator as a stationary source at home, and use portable sources of oxygen when active or in cases of power failure.
The total annual United States payment for care is $6.6 billion. Approximately one-third ($2.3 billion) is due to the cost of LTOT, one-quarter ($1.9 billion) to hospitalizations and inpatient physician services, and one-seventh ($942 million) to nursing home and institutional care. Ineffective treatment as a result of nonadherence can increase resource utilization, and increase the economic burden of an already expensive therapy. Based on these findings, there is little question of the health and economic impact nonadherence has among patients using LTOT.