In a nutshell previous studies have demonstrated an association between low grip strength and poor health outcomes (in other words increased mortality). On the whole previous studies have had too small sample sizes to detect disease specific mortality and have been unable to clearly show relationship with age. The Biobank study has an adequate number of participants, some 500,000, to be able to detect disease and age specific nuances in this relationship.
Some serious math too place in the analysis of the study’s findings and I’m not the one to talk you through the finer details. In essence lower grip strength was strongly associated with adverse health outcomes. This was consistent between gender and remained robust after adjustment for socioeconomic factors. Compared to other commonly used tools grip strength is arguably as reliable as systolic BP and low levels of physical activity to predict a person’s poor overall health.