Intervention to detect hypomagnesemia in patients from Primary Care older 65 years old

Background: Magnesium is considered as an essential mineral for the functioning of the organism. Elderly patients have a multifactorial predisposition to hypomagnesemia. Objective: To establish an intervention to identify elderly primary care patients with hypomagnesemia, and study the financial implications. Methods: In consensus with general practitioners and endocrinology and nutrition specialists, we designed and established an intervention: the Laboratory Information System would automatically register serum magnesium in primary care laboratory requests from patients over 65, if not measured the previous year, or in the current request, and serum availability. The number of new identified cases of hypomagnesemia was counted and the detection rate was calculated by the number of additionally measured serum magnesium tests (N) and the number of identified patients with hypomagnesemia. Finally, the cost in reagent per detected case was calculated, taking into account the reagent price per test ((sic) 0.30) and the number of identified patients (N * (sisc) 0.30 / Number of identified patients). Results: In the six months study period, serum magnesium was measured in 11,749 primary care patients older than 65 and hypomagnesemia was detected in 1,419, being 10% of the cases moderate or severe, identifying more cases with aging. The detection rate was higher when they lived institutionalized (16.0% vs. 11.0%), and the cost per detected case depended on the residence status ((sic)2.5 and (sic)1.9 when at home and institutionalized respectively). Conclusion: The results of the intervention to identify patients with hypomagnesemia by means of an automatic registration of serum magnesium when lab testing request, suggest that it is efficient, especially in older population and when institutionalized.