[Effectiveness and efficacy of self-measurement of capillary blood glucose in patients with type 2 diabetes mellitus].
OBJECTIVE
The efficacy of self-measurement of capillary blood glucose (SMBG) in patients with type 2 diabetes mellitus is not fully established. The objectives of the study were: a) to verify the efficacy of the SMBG in patients with type 2 diabetes mellitus in the primary care set; b) to investigate the possible causes that explain the lack of effectiveness of the method, in their case, and c) to deduce the predictive variables that permit to select good utilizador of the SMBG.


METHODS
Clinical trial controlled and randomized carried out in the environment of the primary care, on type 2 diabetic patients. The patients were assigned, of random form and stratified, according to the type of treatment for diabetes that received, in 2 groups: SMBG group (SMBG-G) and control group (CG). The period of monitoring was of 12 months. The efficacy of the SMBG was analyzed, and also its effectiveness.


RESULTS
100 patients were included in the study. Out of them, 51 were assigned to SMBG-G and 49 to CG. The SMBG was efficient in the 21.6% of SMBG-G and in 14.3% patients of the CG (p = 0.44). The SMBG efficacy was greater in patients with combined treatment and in those who received only insulin (50% in both cases). No improvement was observed in patients on treatment with diet (p = 0.006). The effectiveness for the cut off from value the HbA1c was of 59.2% and of 29.58% for the totality of the European criteria of metabolic control. The independent predictor variables of the SMBG efficacy were: the evolution years number of the diabetes mellitus and a deficient control of the illness at the start of the study. The global precision of the mathematical model obtained was of 88.24% with sensibility of 54.5%, especificity of 97.5%, positive predictor value of 85.7% and negative predictive value of 11.4% (p < 0.001). The area under the ROC curve was of 89.9% (p < 0.001) (95% confidence interval, 81.2-98.5%). According to the ROC curve, the point of cut that better the SMBG efficacy discriminated was that of 74% (sensibility: 72.7%; especificity: 77.5%).


CONCLUSIONS
SMBG is a tool that, although can improve the metabolic control of type 2 diabetes, requires a careful selection of patients and, therefore, cannot be utilized in an indiscriminate way. The time of evolution of the illness and fundamentally, the presence of a deficient metabolic control of the disease should be the factors that determine a good selection. Therefore, its extended use among the type 2 diabetic population, without a prior selection, does not seem to be justified.
Oria-Pino
Amparo
A
Centro de Salud El Higuerón, Córdoba, España. pirdi@telefonica.net
Montero-Pérez
F Javier
FJ
Luna-Morales
Silvia
S
del Campo-Vázquez
Paloma
P
Sánchez-Guijo
Pedro
P
D000368:Aged; D000671:Amputation, Surgical / Q000706:statistics & numerical data; D001786:Blood Glucose / Q000032:analysis*; D002196:Capillaries / Q000378:metabolism*; D015897:Comorbidity; D003924:Diabetes Mellitus, Type 2 / Q000175:diagnosis* / Q000453:epidemiology / Q000378:metabolism*; D005260:Female; D005947:Glucose / Q000378:metabolism*; D006442:Glycated Hemoglobin / Q000378:metabolism; D006801:Humans; D035002:Lower Extremity / Q000601:surgery; D008297:Male; D008875:Middle Aged; D012648:Self Care / Q000379:methods*; D020377:Self Efficacy
D001786:Blood Glucose; D005947:Glucose; D006442:Glycated Hemoglobin