The Christmas season as a risk factor for chronic obstructive pulmonary disease exacerbations
It had been previously observed that exacerbations for COPD increased in the wintertime, particularly during Christmas season, a period that is also characterised by an increased prevalence of viral infections. These observations were based on the fact that healthcare use by COPD patients peaks during the Christmas season. However, it was unclear whether this was due to higher incidence during this period, increased socialisation and risk of infection, or lack of access to normal respiratory care by physicians. The researchers aimed to answer this question, and assess both the incidence as well as determinants of COPD exacerbations in patients from Hamilton, Canada, during the Christmas holiday season (1 Dec 2006 – 17 Jan 2007) vs. the rest of the winter season (18 Jan 2007 – 30 April 2007).
Researchers recruited and monitored 71 patients with a physician diagnosis of COPD with mixed disease severity (GOLD 0–4) who had at least one emergency department visit in the previous year for respiratory symptoms. For the duration of the study, subjects’ medical care remained with their own physicians.
Patients transmitted daily diary sheets using fax machines, which were automatically scanned into a database to alert staff to respiratory symptoms that met specific criteria including increased symptom severity (by 2 levels of severity), symptom severity reaching levels 4 or 5, or patient reported symptoms of a respiratory infection. Compliance was remarkably high, with 95.4% of daily diary surveys returned.
This study reported an average of 6.7 COPD exacerbations per week in study participants (n=71) during the Christmas period compared with 4.3 COPD exacerbations per week during the rest of the study period (p=0.03). In patients with serious COPD (n=23; GOLD 3 and 4) incidence of COPD exacerbations was also higher during the Christmas period than the remainder of the study period (47% vs 32%; p=NS). A total of 44% of Christmas period exacerbations occurred with respiratory viral infections, compared with 32% which occurred during the rest of the study period (p=NS).
The authors speculated that the increased COPD exacerbations during Christmas were not necessarily the result of changes in healthcare resource use, but could be due to increased socialisation and exposure to respiratory viral infections. As travel and increased socialising during the Christmas period is likely to be even more common than it was when this study was first published, it is possible that within the modern NHS, COPD exacerbations in patients at Christmas time may be even more prevalent than previously estimated.