Evaluation of an electronic general-practitioner-based syndromic surveillance system--Auckland, New Zealand,...

During 2000 and 2001, Auckland Regional Public Health Service piloted a general-practitioner-based syndromic surveillance system (GPSURV).

The pilot evaluated data capture, the method used to distinguish initial from follow-up visits, the definition of denominators, and the external validity of measured influenza-like illness trends.

GPSURV monitored three acute infectious-disease syndromes: gastroenteritis, influenza-like illness, and skin and subcutaneous tissue infection. Standardized terms were used to describe the syndromes. Data were uploaded daily from clinics and transferred to a database via a secure network after one-way encryption of patient identifiers. Records were matched to allow the distinction of follow-ups from first visits, based on between-visit intervals of

Physicians' self-reported recording compliance was highest for skin and subcutaneous tissue infection (71%) and lowest for influenza-like illness (48%). Initial visits had 18%-19% greater compliance than follow-up visits. The number of physicians reporting increasing compliance during the pilot was greater than the number reporting decreases for all conditions. Comparison of data with an independent influenza-like illness surveillance system indicated a close agreement between the two data series.

These results indicate that incidence of acute syndromes can be monitored, at least as successfully as a manual system, by using standardized clinical-term data from selected general-practice clinics. The provision of feedback reports appears to have a limited but positive effect on data quality.