Cold temperature and consultations for respiratory and cardiovascular disease.

Abstract

Sirs—The interesting paper by Hajat and Haines¹ illustrates both the advantages and disadvantages of computers. This paper, by sophisticated analysis, shows an association of temperature with consultations for respiratory disease in the primary care setting. The effect was shown to be lagged with some delay in effect. No association was shown for cardiovascular disease consultations. The data used for this sophisticated analysis was based on GP consultations in London in practices co-operating with the General Practice Research database between January 1992 and September 1995. Air pollution, temperature, relative humidity, and pollen data were obtained from a variety of sources representing the conditions in London. A highly sophisticated statistical analysis was performed in order to identify independent association. It is claimed that ‘this study seems unique, in that no previous long-term time-series analysis appears to have been undertaken to investigate the association of consultations with ambient temperature in the primary care setting’.