Evaluation of the surveillance system of chlorination of public water supply in the province of Albacete
Martínez Ferrando, R.; Almar Marques, E.; Mateos Ramos, A.; Navarro Honrubia, C.
Atencion Primaria 15(8): 506-508
1995
ISSN/ISBN: 0212-6567 PMID: 7786975 Document Number: 439847
The aim was to study the reliability of the available data, stemming from the concordance between two different observers' measurement of the level of free residual chlorine. An observational, crossover study, using measurements of the level of free residual chlorine repeated on the same day by two different observers. Health Area of Albacete. 176 double measurements of chlorine, carried out during the study period in 69 networks distributing different waters. Concordance between observers on the absence or presence of chlorination was low (I.Kappa = 0.261), showing a bias in favour of the presence of chlorination in the measurements made by local technicians (McNemar p < 0.01). Applying a logistic regression model, it was observed that the risk of disagreement was as much as 8.5 times greater when chlorine measurement required the local technician to travel. We concluded that the data available was of questionable value and that it would be useful to put forward some new proposals to improve the supervision of the network.