Influenza is a public health problem of global scale that results in a high number of hospital admissions due to both the infectious process and to complications that may derive from it, especially respiratory and cardiovascular.

Although this disease affects all age groups, it is more frequent in children: the frequency in children less than 4 years of age can even double that in the entire population.1 For this reason, most European countries have implemented influenza vaccination strategies that address specific groups at high risk for complications, both in children and adults.2 The Autonomous Community of Valencia has similar vaccination strategies against influenza.1

It is well known that the impact of vaccination programmes depends not only on vaccine effectiveness, but also on the coverage rates attained in the different subsets of the population. However, few studies have analysed the coverage rates by disease in children, and those that have, point at low coverage rates.3,4 With this in mind, the aim of this study was to determine the coverage rate of vaccination against influenza in children aged less than 15 years with heart disease, respiratory disease or diabetes in the Autonomous Community of Valencia during the 2013–2014 season.

We conducted a retrospective descriptive study of the prevalence of the disease and the vaccine coverage, with the corresponding 95% intervals, by age and sex and for each group of diseases under study. To do so, we used the information stored in the Sistema de Información Ambulatoria (Ambulatory Care Information System [SIA]), the primary care electronic medical records database that holds the active diagnostic codes of the patients (IDC9CM), and in the Sistema de Información Vacunal (Vaccine Information System [SIV]), that registers all vaccination acts by the name of the vaccine. From the SIA, we collected the data for patients aged 6 months–14 years with active diagnoses as of August 28, 2013 of heart disease (ICD 393–398, 402–404, 410–416, 424–429 and 746), chronic respiratory disease (490–496, 500–505, 515, 518, V46.2) or diabetes (250, V58.67); and from the SIV we collected and verified the vaccination status of the patients identified in the SIA. We obtained the data for the population aged less than 15 from the Instituto Nacional de Estadística (National Institute of Statistics).

For the purpose of the study, we considered individuals to be vaccinated if the SIV had records of them having received the vaccine between October 1, 2013 and February 28, 2014.

The statistical software used for data analysis was the SPSS® version 15.

Table 1 presents the estimated prevalence by age and sex for the three disease categories.

Fig. 1 shows the vaccination coverage rates achieved for each disease group. Overall, only 11.16% (10.41–11.91) of patients with heart disease, 7.27% (7.10–7.44) of patients with chronic respiratory disease and 24.88% (22.82–26.94) of patients with diabetes had been vaccinated.

Figure 1.

Influenza vaccination coverage by disease, age group and sex. Autonomous Community of Valencia, 2013–2014 season.

(0.26MB).

The overall analysis by sex showed a higher vaccine coverage rate in males for the heart disease group (11.75%; 10.7–12.80) and the chronic respiratory disease group (7.61%; 7.39–7.83).

The analysis by sex and age group offered the following information about the highest coverage rates: in patients with heart disease it corresponded to girls aged 1–2 years (12.85%; 9.38–16.32); in patients with respiratory disease, boys aged 10–14 years (9.10%; 8.65–9.55); and in patients with diabetes, boys aged 3–4 years (34.29%; 18.56–50.02).

The prevalences of disease that we found were consistent with the prevalences expected based on the 2010 Autonomous Community of Valencia Health Survey,5 which reduces the probability of having underestimated the coverage rates.

As for vaccination coverage, the rates found were low: they did not reach 25% in any of the age, sex, or disease groups.

The results we obtained are consistent with those of other studies in our country,3,4 which suggests that this situation is commonplace in all of Spain. This is a surprising fact considering the unanimous recommendations with regards to vaccination, and because coverage rates for childhood immunisation programmes are consistently high in Spain.6

In conclusion, despite the recommendations for vaccination against influenza aimed at high-risk groups in children and the existing knowledge of diagnoses in primary care, the achieved coverage rates are very low. We believe that the dissemination of coverage rate results, the explicit inclusion of chronic diseases in care protocols, vaccine recommendations and the use of the alert mechanisms available in many information systems could contribute to the improvement of coverage rates.