Is it worth indexing GFR to body surface area?
Am Soc Nephrol J Am Soc Nephrol (abstract) (Sep) 7:1582 1996 Physiologic parameters such as GFR are often indexed to body surface area (BSA), i.e. the parameter is divided by BSA and multiplied by 1.73, the idealized BSA. This is based on the presumption that many physiologic functions are proportional to BSA and that indexing will remove variations based on size and weight, and clarify true variations in physiologic function. The study of Juillard et al. is clearly a response to the intriguing and provocative study from another group, Turner et al.(1) The latter assert that indexing of variables such as GFR for BSA is “devoid of statistical foundation” and may at times lead to the appearance of spurious correlations, and in other circumstances may obscure the presence of true correlations. It was proposed that indexing of a variable for BSA would be appropriate only when a linear regression plot of the variable against BSA revealed a significant positive correlation, and a Y- intercep
