Study objective: To contrast the effectiveness of 2- vs 6-month reevaluation intervals on both clinical outcome and cost in patients requiring continuous home oxygen therapy (HOT).
Design: Prospective, randomized clinical trial.
Setting: The outpatient program of a university-affiliated Veterans Affairs Medical Center (VAMC) Pulmonary Service.
Patients: Fifty patients were chosen from among a cohort of 200 patients currently enrolled in our HOT program. All met specific arterial blood gas criteria, were able to give informed consent, had at least 6 months of prior HOT usage, and did not have any illness expected to independently shorten life expectancy.
Interventions: Baseline resting oxygen flow rates were prescribed based on the results of arterial blood gas measurements so as to attain a PaO2 > 60 mm Hg. Flow rates were adjusted as needed during a 12-min walk to maintain pulse oximetry readings > 90%. No adjustments in baseline flow rates were made during sleep. Identical evaluations were repeated at either 2- or 6-month intervals.
Measurements and results: At 1-year follow-up, there were no significant differences between the 2- and 6-month groups in any of the clinical outcome parameters measured, ie, number of emergency department visits, number of hospitalizations, number of days hospitalized, or mortality. Total costs were not significantly different between the two groups. Evaluation costs were less in the 6-month follow-up group.
Conclusions: After attaining stability following at least 6 months of continuous HOT usage, patients receiving continuous HOT need not be routinely reevaluated more frequently than every 6 months.