Page 194 - Timeliness of Infectious Disease Notification & Response Systems - Corien Swaan

192 Chapter 9
substantially. Still, the delay of notification after laboratory confirmation is of concern for botulism, diphtheria, hantavirus infections, leptospirosis, malaria, community acquired MRSA (MRSA CA) and STEC.
Reporting delay
The Centre for Infectious Disease Control (CID/RIVM) monitors reported cas- es in Osiris to identify supra-regional or national outbreaks. In Chapter 5, we showed over the period 2013-2017 a median reporting delay from MHS to the RIVM (D6) of 0 days, range 0-1 day, and an average across the medians of 28 diseases of 0.1 day. In 2016-2017, 98.4% of reported cases were within the legal timeframe of the specific disease. This is in line with our earlier observation that all MHS reported ≥ 90% of cases within the disease specific timeframe to the RIVM in 2014 (7). Nevertheless, for some specific diseases, the percentage of disease reported beyond the indicated timeframe was substantial, such as for diphtheria (33.3%) and MRSA CA (55.6%). This is probably due to the time need- ed to collect more information to determine whether the case fulfills reporting criteria to the RIVM.
Threshold for timeliness of notification and reporting delays
We described the notification and reporting delays in the Netherlands, and to which extent they meet the legal timeframe. But when can we conclude that notifications are timely enough? What do we consider as appropriate threshold for timeliness? Universal thresholds for performance indicators for notification and reporting delays are not available. According to the WHO tool for the Joint External Evaluation (JEE), with regard to surveillance capacity, a country is ex- pected to have data on completeness and timeliness of reporting from at least 80% of its reporting units (8). In our systematic literature review in Chapter 3, authors provide a variety of timeframes in evaluation of notification systems; however they do not provide thresholds when these timeframes are met suf- ficiently. In the Netherlands, the Inspectorate delegated the monitoring of re- porting timeliness to the RIVM, aiming at timely reporting of 100%. The RIVM uses 80% as threshold, considering reporting timeliness insufficient if the per- centage of timely reports of the MHS is below 80%. For this thesis, in Chapters 3 and 5, we chose the following thresholds for timely notification and report- ing: ≥ 80% of cases in time according to the timeframe: sufficient; between 50%-80% in time: partly sufficient; and < 50% in time: insufficient. One could argue that these cut-offs are rather relaxed, as with the lower limit of 50%, up to half of the notifications are not within the timeframe. However, our litera-