It may come as a surprise to discover South Australian heart failure patients are more likely to die during the State's mild winters than its scorching summers.
But Australian research published recently in the European Journal of Heart Failure reflects what seems to be a global phenomenon - that chronic heart failure (CHF) patients are more likely to die or become seriously ill in winter than summer; and that it is relative, rather than absolute changes in temperature and climatic conditions that are a driving factor.
The local findings are based on an examination of the death and hospital admission records of almost 3000 CHF patients in South Australia over more than a decade.
It is the first study of its type in the southern hemisphere, according to UniSA Adjunct Lecturer and Director of Clinical Pharmacology at the Royal Adelaide Hospital, Dr Sepehr Shakib, who undertook the study with the lead researcher, University of Queensland PhD candidate and UniSA alumna Sally Inglis, and a team of researchers around Australia including Dr Robyn Clark from UniSA's School of Health Sciences.
"The pattern of CHF patients coming into hospital a lot in the winter months mirrors that seen in studies conducted in much cooler northern hemisphere climates such as Scotland and Canada," Dr Shakib said.
While CHF-related hospitalisations and deaths peaked in winter and were actually at their lowest in summer, Dr Shakib said the causes were more likely to be the "social things that go on around winter" than temperatures alone.
"Many of the patients we followed were elderly, with middle-aged carers who often also have children they care for. If cold and flu goes through the community, the carers turn their attention to the children and are then less available to care for the older people, who often end up coming into hospital," he said.
"Also, if you want to visit your GP in the middle of winter, you might have to wait four or five days. The GP might have been able to prevent you coming into hospital if he'd seen you within two days, but the two or three day delay means that you actually come into hospital much sicker."
Dr Shakib said for many CHF patients, who often have multiple other medical conditions, an extended period of hospitalisation has a serious impact on the patient's overall quality of life.
"CHF has a very bad prognosis, worse than most types of cancers," he said.
"In fact, most chronic CHF patients will die within two years of hospitalisation. A few weeks of illness that end with a week or so in hospital might be of a month out of their lives. And so avoiding that hospital admission is really important."
The increase in admissions also has a dramatic impact on hospital workloads, which has been measured at 50 per cent heavier during winter.
"This is actually a cyclic phenomenon and so it affects the burden on staff and hospital facilities," Dr Shakib said. "Understanding some of the reasons for the increase in admissions during winter allows us to better organise healthcare resources to cope.
"It also means we might be able to restructure the healthcare workforce differently, so that what staff do differs in the summer and winter months."
Dr Shakib said the Royal Adelaide Hospital has already begun actively recruiting CHF patients from wards into programs that focus on improving heart health and management. Other possible initiatives to reduce CHF patient hospital admissions, he suggested, included changing the routine of outpatient consultations to take into account risks associated with winter; setting up services for the CHF patients to be more closely managed; making telephone monitoring services available; and, importantly, ensuring patients and their carers are vaccinated against influenza in autumn.
"Seventy five percent of the total cost of heart failure management is just being in hospital," Dr Shakib said. "Trying to prevent CHF hospitalisations is not only better for patients, but also for the effectiveness of the public health system."
Fir more UniSA research news go to http://www.unisa.edu.au/unisanews/
