Patient Survival: How rates are calculated?

September 20, 2009 by admin

A certain number of deaths are expected in any group. For patients of a dialysis facility, this number is affected by the patients' age, size, race, sex, ethnicity, whether or not they have diabetes, how long they have had renal failure, and whether they had other health problems when they started dialysis. To calculate the expected number of deaths for a patient, multiply:

The expected deaths are calculated for all patients in the facility to give the total number of deaths expected for the 4-year period at the facility. Actual compared to expected To calculate the relative patient mortality, divide:

The margin of error is accounted for as described in the example below to be sure that random errors do not account for the reported results. *Deaths due to street drugs and accidents are not included because they are not related to the care and treatment received at the facilities. Margin of Error (Confidence Interval) When determining the relative patient mortality, there is a margin of error. Differences between the actual and expected number of deaths must be outside the margin of error, or the facility is rated as having survival 'As Expected'. Example: Facility DEF has 100 patients. 10 Patients die during the 4 year time period. 1. The expected number of deaths, (considering the facility's patients' age, size, race, sex, ethnicity, whether or not they have diabetes, how long they have had renal failure, and whether they had other health problems when they started dialysis.) is 21.6. 2. There were only 10 deaths at the facility, which is less than the 21.6 deaths expected. 10 (actual number of deaths) ÷ 21.6 (expected number of deaths) = 46% of the expected death rate. This is 54% (=100%-46%) better survival than expected. 3. The confidence interval is (22%, 85%) The confidence interval is used to account for the margin of error. It indicates that the death rate was somewhere between 22% and 85% of what was expected. This means that the survival at the facility is somewhere between 15% (=100%-85%) and 78% (=100%-22%) better than expected. 4. The survival at the facility is at least 15% (=100%-85%) better than expected. Facility DEF's patient survival rate is 'Better than Expected'.