As the aging population in the U.S. continues to expand, the life insurance industry has enhanced its focus on the risks associated with underwriting older applicants. This is particularly so when determining the level of kidney functionality among older applicants and its direct correlation to mortality rates within this demographic.
The increased attention on the elderly market has had a positive effect on underwriting decisions on older applicants. In addition, it will improve testing processes in the long term to the benefit of younger generations.
When evaluating kidney functionality, underwriters use several serum and urine test values to help assess the overall mortality risk of a proposed insured. One of the most debated of these values is the “estimated glomerular filtration rate” (eGFR). As its name suggests, it’s an estimate, not an exact measurement, and mortality assumptions can be significantly impacted by small changes to the eGFR.
The eGFR is based primarily on the concentration of serum creatinine in the blood. Serum creatinine results from the breakdown of creatine in the muscles and is excreted from the body by the kidneys.
The measure of creatinine cleared during a 24-hour period defines the creatinine clearance and correlates directly to the level of kidney function. In cases of renal disease, or where kidney damage or obstruction exists, creatinine clearance values fall. This suggests the degree of failure by the kidneys to eliminate waste and regulate the volume of body fluid.
Calculating the creatinine clearance from a blood specimen provides the underwriter with a snapshot of kidney function, but it can be “out of focus” with reality. The eGFR is the best estimate of this capability, since 24-hour urine collections are impractical, and there can be issues with accuracy in collection.
The original iteration of the eGFR calculation to determine estimated creatinine clearance used age, weight and gender to massage the serum creatinine value.
Another earlier method used race as an additional factor, based on studies available at the time that were race-based. This method often resulted in distinct differences by race when considering African Americans versus Caucasians. Since race can no longer be considered in insurance determinations and is generally transparent to the underwriter, it is not reasonable to consider for eGFR calculations.
The third and most commonly used method by many companies today disregards both race and weight. Since race cannot be used as a determinant factor in underwriting the risk and, since fat does not contribute to increased levels of creatinine in the body, the argument here is that weight should also not be a factor in evaluating proposed insureds.
Regardless of the test’s accuracy, there are other factors that can alter the result. A more favorable eGFR can result from artificially low serum creatinine levels caused by malnutrition, vegetarian diets, amputation or paraplegia, to name a few.
Additionally, unfavorable results can derive from artificially high serum creatinine caused by muscular build (or low body fat) and some medications such as cimetidine (Tagamet, which is generally available over-the-counter) or trimethoprim (Bactrim).