This study showed that regular phone call reminders significantly enhanced timeliness of reports in this particular electronic disease surveillance system. Our findings suggest that phone calls might correct forgetfulness of notification, which was identified as an important determinant of reporting delays by surveillance personnel. Given that health care providers in clinical settings are usually overloaded with many tasks, disease reporting is not considered a top priority, particularly in developing countries. Thus, contacting reporting personnel a few hours before the deadline was shown to be the key strategy to reach better report on time rates, even when the duration of phone calls was less than two minutes on average. On the other hand, monthly supervision visits allowed closer contact with reporting personnel, but did not show significant improvement in timeliness, probably because of their limited frequency. Occasional visits to those who provide the data is a common activity in successfully implemented systems [2
]; however, its use should be carefully considered by system administrators when the priority is improvement in timeliness.
There are factors intrinsically related to military settings that might have contributed negatively to timely surveillance in this sample. For example, frequent deployments away from home and restriction of communications during missions could generate unintentional epidemiological silence. In addition, limited access to reporting tools such as computers with internet access also affects timeliness in electronic-based surveillance systems, especially in developing countries where availability of technology is not widespread [20
Despite the fact that no outbreaks were detected during the study, it logically follows that enhancing timeliness in the phone group would have led to more rapid outbreak detection. Surveillance systems that diminish notification delays improve their capacity for detecting outbreaks and allow the triggering of more appropriate responses [9
]. Military and other confined populations are of special concern because they are often exposed to conditions favoring the transmission and perpetuation of pathogens [22
]. Moreover, the need for early disease detection systems in these settings is increasing as the potential for pandemics persists and studies have shown that military populations played an important role in the origin and explosive expansion of pandemic agents in the past – in the US, the influenza pandemic of 1918–19 began among military trainees [23
The effect of supervision visits on data quality differed in clinics when compared to ships. Previous studies have shown that regular training decreases reporting errors [25
]; however, in our study, there was no beneficial effect of briefly training personnel during supervision visits performed on the ships. It is possible that because ships had less experience (time) using the Alerta system, visits did not improve data quality on the ships as they did in the clinics. More intensive monitoring and training may be needed in these newly incorporated sites. The lack of improvement in data quality on the ships might also be partially explained by inherent adverse conditions that exist on Navy ships, such as frequent personnel turnover, frequent accidents and frequent deployments with limited access to assistance.
Although electronic-based notification often enhances data quality [9
], Alerta reporting personnel perceived that the system's platform itself generated errors. However, the data did not corroborate this perception. Perceived barriers for the implementation of biotechnologies have been described in developing countries [20
], including the difficulty in replacing traditional pen and paper reporting systems with technological solutions that are not commonly used. This negative perception of technology is very important to address in order to assure successful adoption of technology among users and thus favor the optimal implementation of an electronic-based system in developing countries [27
This study had some limitations. We performed 170 calls in the phone group during the study period, but 16.5% of the calls were not successful (reporting personnel did not answer or were absent from the unit despite at least three attempts to contact them before time deadline). Although there was a small sample size, we did a total of 24 measures of EPTR and ROTR before and during the interventions for each site. The use of generalized linear models (GLM) for binomial data allowed us to calculate the impact of the interventions considering these pre and post measures in each reporting unit maintaining a clustered analysis. Finally, specific characteristics in this sample might affect the reproducibility of our results in other settings. For example, health care providers in the Alerta system are also charged with disease notification, which differs from the majority of other surveillance systems in the region where administrative personnel provide notification. In addition, constant deployments and frequent missions might negatively affect timeliness and data quality of reports in this sample, especially among ships when they are underway.
Further investigations are needed to establish the cost-effectiveness and optimal use of telephone reminders and visits. Moreover, interventions such as automated telephone or text messaging reminders and retraining/monitoring through video-teleconference might be explored. However, potential perception barriers against these technological solutions should be considered in resource-limited settings when trying to apply automated interventions. With respect to this, we feel that the person-to-person interaction during the telephone reminders and visits played an important role in our results, as they allowed strengthening ties between reporting personnel and the central hub and possibly enhanced the perception of ownership among reporting personnel.