Reduction in natural death and renal failure from a systematic screening and treatment program in an Australian Aboriginal community.

BACKGROUND

Australian Aborigines in remote areas are experiencing an epidemic of renal and cardiovascular disease. In November 1995, we introduced a renal and cardiovascular treatment program into the Tiwi community, which has a three- to fivefold increase in death rates and a recent annual incidence of treated end-stage renal disease (ESRD) of 2760 per million. Our previous study described an estimated 50% reduction in renal failure and all-cause natural deaths in the treatment group through December 31, 1998. We now describe a reduction in these events through mid 2000.

METHODS

People eligible for treatment were those with confirmed hypertension, diabetics with microalbuminuria or overt albuminuria, and people with overt albuminuria, regardless of blood pressure and diabetes. Treatment centered around the use of perindopril (Coversyl, Servier), with additional agents as needed to reach defined blood pressure goals, attempts at control of glucose and lipid levels, and health education. Two hundred and sixty-seven people, or 30% of the adult population, have been enrolled, with mean follow up of 3.39 years. Rates of terminal endpoints were compared on an intention-to-treat basis with those of 327 historical controls matched for baseline disease severity, who were followed for a mean of 3.18 years in the pre-treatment program era, against a background of no treatment or inconsistent changing treatment.

RESULTS

Terminal events occurred in 38 controls and 23 people in the treatment group. The estimated rate of natural deaths in the treatment group was 50% that of the controls, (P=0.012); the rate of renal deaths was 47% (P=0.038) and the rate of non-renal deaths was 54% that of controls (P=0.085). Survival benefit in the treatment group was observed at all levels of overt albuminuria, in non-diabetics and diabetics, in normotensive as well as hypertensive people, and in people who had been taking angiotensin converting enzyme-inhibitors (ACEi) in the pre-program era, as well as those who had not. Benefit was absent among the low death rates of people without overt albuminuria, and questionable among people with glomerular filtration rates (GFRs) <60 mL/min. The number of people needed to treat (NNT) to avoid one terminal event of natural causes was calculated at only 11.6.

CONCLUSIONS

Falling rates of deaths and renal failure in the whole community support marked benefit of the program. Millions of dollars have been saved, based on avoidance of dialysis alone, but the reduction in premature death is the greater benefit. Chronic disease programs like this are enormously effective, and should be introduced into to all high-risk communities as a matter of urgency.