Reagent matrices and methods are disclosed for improving the stability of test elements with respect to degradation by humidity in the air. The reagent matrices and methods are based upon using an effective amount of a deliquescent material to decrease the sorption of water from the air by other components of a reagent matrix. When the test element is a glucose-specific test strip, and the reagent matrix can include a glucose dehydrogenase enzyme and/or a flavin adenine dinucleotide cofactor, a nitrosoaniline mediator, and a film former, where the deliquescent material may include a salt such as sodium chloride in an amount effective to absorb water from the atmosphere at a rate that is faster than the rate at which the other components of the reagent matrix absorb water from the atmosphere.