Estimating the Coverage of Systematic Vaccinations among the Balearic Island Infant Population

Abstract

Background: In order for vaccination programs to be carried out properly, it is essential for the vaccination coverage to be known. On the Balearic Islands, the reported coverage was much less than for the rest of Spain. The objective of this study is that of estimating the coverage of the vaccinations included on the recommended schedule up to 18 months of age (4 doses of oral polio, tetanus and diphtheria; 3 doses of whooping cough; 1 dose of measles, rubella and mumps). Methods: A descriptive, cross-sectional study of the population base. The ideal-time frequency distribution estimators and the corresponding confidence intervals were calculated at 95% (CI95%) for a sample of the resident two-year-old (born in 1995) Balearic Island population selected by means of a single-stage conglomerate random sampling based on census sections. The National Public Health System and National Health Institute vaccination records were reviewed, the data from the vaccination document having been requested from the families and the clinical record from the private pediatricians by telephone. Results: The sample included 606 children, it having been possible to obtain full information on 532 children. Full information was obtained on 377 cases (62%) from the public health sector records. The least degree of coverage was found for the diphtheria vaccine, 518 children having been fully vaccinated, 96.8% (CI95% = 94.8 98.1), the highest degree of coverage having been found for the whooping cough vaccine, 537 children, 98.9% (CI95% = 97.5 99.5). Conclusions: Good vaccination coverage was found to exist on the Balearic Islands, being similar to what has been being estimated for Spain as a whole. The objective included within the Polio Eradication Plan is accomplished, very little information being gathered from the public sector.