Background: The 19 Norwegian Emergency medical communication centres (EMCCs) use Norwegian Index for medical emergency assistance (Index) as dispatch guidelines. Little is known about the use of Index, nor its validity. We aimed to document the epidemiology of contacts made to the public emergency medical phone number and the operators' self-reported use of Index as a first step towards a validation study.
Methods: We registered all medical emergency calls to the EMCCs during a 72 h period in a national cross sectional study. We subsequently sent a questionnaire to all EMCC operators in Norway, asking how they use Index. A combined outcome variable "use of Index" was computed through a Likert scale, range 1-5. Regression models were used to examine factors influencing use.
Results: 2 298 contacts were included. National contact rate was 56/1,000 inhabitants per year, range between EMCCs 34 - 119. Acute contact (life-threatening situations) rate was 21/1,000 per year, range between EMCCs 5 - 31. Index criteria 6 - 'Unresolved problem' accounts for 20% of the 113 contacts, range between EMCCs 10 - 42%. The mean use of Index was 3.95 (SD 0.39), corresponding to "more than 75% of emergency calls". There were differences in use of Index on EMCC level, range 3.7 - 4.4, and a multi regression model explained 23.4% of the variation in use. Operators working rotation with ground ambulance services reported reduced use of Index compared to operators not working in rotation, while distinct EMCC focus on Index increased use of Index compared to EMCCs with no focus on Index. Use of electronic records and operators experience were the main reasons given for not using Index.
Conclusions: There is a large variation between the EMCCs with regard to both contact patterns and use of Index. There is a relatively high overall self-reported use of Index by the operators, with variations on both individual and EMCC level.