Equating eGFR Levels And Renal Function In Impaired Risk Cases

There is a belief that this most commonly used method for calculating eGFR tends to create more “false positive” results because there are more factors that can lower the value rather than raise the value. However, this theory does not validate the specific results of some proposed insured clients that fall on the “false negative” side of the equation and would generally be more adversely underwritten.

Producers may wish to question an adverse decision as it relates to questionable kidney function if the producer is aware that the client has a muscular build and knows which medications the client is taking. Raising the question alone may not invalidate the mortality assumption, but it may necessitate evaluation by, and opinion from, the proposed insured’s physician in some cases where the findings could be explained by physical build or medications.

An additional factor that has been questioned is how the age of a proposed insured impacts the testing process. Laboratories disagree to some extent on this factor. Some suggest that one’s age causes no significant change in the results, but others claim that lower eGFR at older ages is a reasonable outcome. This question may need more study to be resolved, but it demonstrates the concern with the calculation.

Given the disagreements on the normal eGFR ranges expected for gender, the differences, though relatively small, demonstrate yet another element that is not entirely clear across all industry experts.

As a general rule, laboratory differences based on materials that are used to test elements of serum should not alter the rating outcome, depending on the insurance company’s use of laboratory results. But inherent in the insurance process is the existence of external factors that can artificially inflate serum creatinine results when tested in the laboratory and, therefore, any eGFR calculation.

For instance, delays in processing fluids can create artificially-high values due to glycolysis (breakdown of glucose in the serum over time) or heat exposure. The resulting high serum creatinine values create a poorer picture of renal function with the eGFR calculation. While glycolysis is evident and reported by insurance laboratories on specific specimens, the only suggested indicator for heat exposure is the time delay from collection to processing and there is no test to validate that possibility.

Even when a known delay exists in the processing or glycolysis of the serum, it should not automatically invalidate the specimen or the mortality assumptions of the case. The condition of the serum may suggest that further testing is needed by the personal physician; the goal would be to assess accurately the kidney function depending upon extent of kidney function abnormality and the specific facts on specimen handling.

Underwriting is not an exact science, and science relative to renal testing does not make underwriting any easier to navigate. The art form of underwriting, when properly used, must consider the variables and all aspects of the case before reaching the best decision on the risk to be accepted.

Sometimes, when going “by the book” is simply not the best approach, the art of underwriting can be implemented with the intention of making every rating decision as accurate as possible.

Everett Kunzelman is vice president and chief underwriter, and Clifford Hale is vice president and chief medical officer, for Jackson National Life Insurance Company, Lansing, Mich. Their respective e-mail addresses are [email protected] and [email protected].