Underlying condition increases H1N1 risk

OTTAWA, Feb. 16 (UPI) -- The risk of death increases by 5.5 percent in the time between when the symptoms of H1N1 start and hospital admittance, Canadian researchers found.

Dr. Rachel Rodin of the Public Health Agency of Canada and colleagues examined the records of all patients in Canada admitted to hospital for H1N1 in the first five months of the outbreak.

The study looked at 1,479 people admitted to hospital, including the intensive care unit with confirmed H1N1.

"All 13 provinces and territories in Canada participated in an active national surveillance system that captured all cases of laboratory-confirmed pandemic H1N1 influenza in patients admitted to hospital or who died," Rodin said in a statement.

The study, published in the Canadian Medical Association Journal, found the risk of death increased by 5.5 percent with a delay of one day in the time between when the symptoms started and when the patient was admitted to the hospital. The risk of a severe outcome remained constant over a five-month period.

The risk of a severe outcome among patients admitted to hospital with H1N1 was elevated among those who had an underlying medical condition and patients age 20 years and older -- with patients 65 and older at the greatest risk for death.