Objectives: To determine adverse clinical events and resource utilization associated with culture-positive influenza A in nursing home residents.
Design: A retrospective cohort study with cases and controls.
Setting: Seven hundred twenty-one-bed skilled nursing facility.
Participants: One hundred fifty-four residents (21% of all residents) from whom influenza A was isolated during the 1997/98 season and matched controls.
Measurements: Baseline parameters, staff interventions, diagnostic tests, and adverse events were recorded from 60 days before to 60 days after specimen collection. The difference between each individual's before and after measurements determined excess utilization secondary to influenza. Controls were studied to determine time series effects.
Results: Baseline Minimum Data Set and nutritional parameters demonstrated significantly greater (P <.05) feeding dependency and lower serum albumin in the control group. Time series effects in the control group were negligible. Among cases, there were nine deaths within 30 days; among controls, there were four (chi2 P =.26). Within 30 days of onset, an average excess of 18 notations by nursing staff, one phone call to the physician, and one to family was noted per case. In half of cases, a nonscheduled physician visit was required. There was a 20% excess in physician orders for oxygen and bronchodilators. Chest x-rays were performed in half of the cases, and antibiotics were prescribed to half. Sixteen percent of cases had radiographic pneumonia, and 2% had congestive heart failure. The average cost for excess chest x-rays, laboratory services, antimicrobials, ambulance calls, hospital days, and emergency room and physician visits was $943.44. This does not include efforts by nursing home staff who accommodate functional decline on-site.
Conclusion: An unexpected finding was that there were more impaired individuals who were less likely to have influenza detected or less likely to acquire influenza in the control group than in the influenza group. The morbidity, mortality, excess staff effort, and measured expenditure justify efforts to prevent influenza.