Deprived patients carry winter COPD admission burden
medwireNews: Interventions to reduce winter hospital admissions for chronic obstructive pulmonary disease (COPD) should be targeted at the most economically deprived patients, say researchers who found that this group is disproportionally affected by the seasonal impact of the disease.
Using 10-year data from Scotland, the team observed that in all four seasons of the year, there were wide differences in admission rates between the most deprived quintile and the least deprived quintile.
For example, in summer, respective admission rates were 120 and 23 per 10,000 people, while in winter they were 159 and 31 per 10,000 people. This also resulted in an exaggerated winter-summer difference in admission rates among the most deprived patients at 39 per 10,000 compared with just eight per 10,000 in the least deprived patients.
And, the authors found evidence of an additive interaction between deprivation and season, such that the interaction was responsible for 19.4% of the increased risk for admissions among the most deprived patients.
Analysis of admissions against temperature changes also yielded similar relationships, with the authors estimating that for each 5°C decrease in average daily minimum temperature, the monthly relative risk for admission among the most deprived group versus the least deprived group is 83% higher than if there had been no interaction.
Overall, the authors estimate that if the effects of winter were eliminated, an additional 320 COPD admissions per 100,000 people would be prevented in the most deprived quintile over the least deprived quintile each year.
The team, led by David McAllister (University of Edinburgh, UK), says that while it is known that both deprivation and seasonality are associated with hospital admissions for COPD, an interaction between the two has not previously been reported.
They suggest that the effect may be due to more deprived patients having greater difficulty maintaining sufficient warmth at home during the winter. Additionally, indoor air quality may be worse in deprived areas, which could become a more important factor in the winter. And the authors also propose that, as airflow limitation is associated with deprivation, susceptibility among those with underlying COPD may be unmasked by winter-related factors.
"Our findings imply that population-wide interventions aimed at reducing winter admissions with COPD (such as winter fuel benefits or subsidised home insulation) may have potential for greater benefit if delivered to more deprived groups," they conclude in the Primary Care Respiratory Journal.
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By Kirsty Oswald, medwireNews Reporter