[An analysis of the reliability of a data-gathering form. An interobserver concordance study].
OBJECTIVE
To measure the reliability of a data-gathering from by analysing the concordance between observers, and to check the efficacy of the corrective measures applied to improve it.


METHODS
A pre-test/post-test design, without a control.


METHODS
Urban Health Centre.


METHODS
Random selection of 50 clinical records from the list of Type 2 diabetics in the centre's computerised files.


METHODS
Alterations in the data-gathering form in order to improve concordance between two independent observers, measured by means of the Kappa index for qualitative variables and absolute concordance for quantitative ones. The quality criteria defined by the Diabetes in Primary Health Care Study Group were applied.


RESULTS
The Kappa index average improved after the intervention from 0.71 to 0.89 (p = 0.019). There were no significant changes in concordance for quantitative variables (6 out of 8 items with 100% concordance at start and finish).


CONCLUSIONS
It is important to verify the reliability of the measuring instruments. Our results justify this concern: two independent observers do not always obtain the same reading from the same source. Concordance improved significantly when the form was altered, so guaranteeing greater data-gathering reliability and improving the overall quality of the research.
Sánchez Ramos
J L
JL
Centro de Salud Molino de la Vega, Huelva, Unidad Docente de Medicina Familiar y Comunitaria de Huelva. udhuelva@leader.es
Hidalgo Salvador
J A
JA
Romero Andivia
E
E
Calvo Lozano
J
J
D003625:Data Collection / Q000592:standards / Q000706:statistics & numerical data*; D003924:Diabetes Mellitus, Type 2; D005568:Forms and Records Control / Q000592:standards / Q000706:statistics & numerical data; D006801:Humans; D008499:Medical Records / Q000592:standards / Q000706:statistics & numerical data*; D015588:Observer Variation; D011786:Quality Control; D015203:Reproducibility of Results