Waning protection of influenza vaccination during four influenza seasons, 2011/2012 to 2014/2015

BACKGROUND

Concerns have been raised about intraseasonal waning of the protection conferred by influenza vaccination.

METHODS

During four influenza seasons, we consecutively recruited individuals aged 18years or older who had received seasonal influenza vaccine and were subsequently admitted to the hospital for influenza infection, asassessed by reverse transcription polymerase chain reaction. We estimated the adjusted odds ratio (aOR) of influenza infection by date of vaccination, defined by tertiles, as early, intermediate or late vaccination. We used a test-negative approach with early vaccination as reference to estimate the aOR of hospital admission with influenza among late vaccinees. We conducted sensitivity analyses by means of conditional logistic regression, Cox proportional hazards regression, and using days between vaccination and hospital admission rather than vaccination date.

RESULTS

Among 3615 admitted vaccinees, 822 (23%) were positive for influenza. We observed a lower risk of influenza among late vaccinees during the 2011/2012 and 2014/2015A(H3N2)-dominant seasons: aOR=0.68 (95% CI: 0.47-1.00) and 0.69 (95% CI: 0.50-0.95). We found no differences in the risk of admission with influenza among late versus early vaccinees in the 2012/2013A(H1N1)pdm09-dominant or 2013/2014B/Yamagata lineage-dominant seasons: aOR=1.18 (95% CI: 0.58-2.41) and 0.98 (95% CI: 0.56-1.72). When we restricted our analysis to individuals aged 65years or older, we found a statistically significant lower risk of admission with influenza among late vaccinees during the 2011/2012 and 2014/2015A(H3N2)-dominant seasons: aOR=0.61 (95% CI: 0.41-0.91) and 0.69 (95% CI: 0.49-0.96). We observed 39% (95% CI: 9-59%) and 31% (95% CI: 5-50%) waning of vaccine effectiveness among participants aged 65years or older during the two A(H3N2)-dominant seasons. Similar results were obtained in the sensitivity analyses.

CONCLUSION

Waning of vaccine protection was observed among individuals aged 65years old or over in two A(H3N2)-dominant influenza seasons.

[Clinical safety plan in a university hospital complex. Initial diagnosis: study of adverse events]

OBJECTIVES

To establish the incidence of adverse events (AEs) and incidence of patients with AEs in the University Hospital Complex of Albacete (CHUA); to identify and define the AEs which are linked to health care; to analyse avoidable AE and determine their impact; to plan improvement actions.

METHOD

.

DESIGN

Retrospective cohort study.

SAMPLE

Patients registered from 5 November to 19 November, 2007.

CASE DEFINITION

Any accident or incident reported in the medical record which injured or may have injured the patient.

MATERIAL

Adverse Events Screening Guide, adapted from the Harvard study. Spanish version of the Modular Review Form (MRF2) for retrospective case record review.

STATISTICAL ANALYSIS

Univariate and bivariate analysis and logistic regression model.

RESULTS

The incidence of patients with AEs linked to hospital care was 6.8%. The incidence was significantly different depending on: age, presence of intrinsic or extrinsic risk factors (excluding peripheral venous catheter); 8.2% of AE was linked to care; 14.3% to medication; 26.5% to nosocomial infections; 35.7% to technical problems in procedures; 11.2% to diagnosis, and the remaining 4.1% to other types of AEs. In these incidences, 12.2% were considered mild, 78.6% moderate and 8.2% serious. Half (50%) of AEs caused an increase in hospital stay, and in 34.7% cases determined hospitalisation. A total of 63.3% of AEs were considered avoidable.

CONCLUSIONS

The study of AEs in the CHUA represents an improvement within the hospital quality program. Incidences of patients with AEs and those related to health care fall within the range of those found in the studies where the objective was quality improvement.

[Factors that contribute to health care associated infections: how to prevent them]

OBJECTIVE

To determine the patient and medical care characteristics of Health Care-Associated Infections (HCAI) and to determine whether or not there are any differences between those that may be avoidable.

METHOD

A retrospective cohort study, based on three Spanish cohort studies of Adverse Events associated with hospitalization. The medical records were reviewed to assess whether or not the health care was the causing factor of the HCAI. We carried out the analyses using the same methodology as the National Study on the Adverse Effects associated with hospitalization (ENEAS). After reviewing the patient medical records to identify the HCAI associated factors, the reviewers gave a valued judgment on how likely the health care was the cause of the infection (HCAI) and whether there was evidence that they could have been avoided.

RESULTS

A total of 2.3% the patients in the study had one or more HCAI, with 60.2% of them being avoidable. The patients who had an HCAI were older and had a greater number of intrinsic and extrinsic risk factors. There was a significant difference in the presence of some intrinsic risk factor between patients who had an HCAI and those with an avoidable HCAI, but there were no differences as regards medical care extrinsic risk factors. The factors that best explained the HCAI were different for each one of the most common infection locations. Generally, the factors which best explained the HCAI were: urinary catheter (OR=2.4), nasogastric tube (OR=1.9) or central venous catheter (OR=1.8). Similarly, hospital admissions through a surgery department or a hospital stay longer than a week were identified as main factors, (OR=1.6), (OR=7.5), respectively. The best strategies to avoid an HCAI were: proper management of any aseptic technique and use of catheter (25.5%), a proper follow-up of the bladder catheterisation protocols (20%) and a proper health care follow-up of vulnerable patients (16.5%).

CONCLUSION

Patients with an HCAI showed significant different characteristics from those who did not have an HCAI. The preventability is an independent valued judgment from the causality, and is associated to whether the proper protocol has been implemented or not. To identify these weaknesses enables us to establish strategies to improve the quality of medical care.

Prevalence of adverse events in the hospitals of five Latin American countries: results of the 'Iberoamerican Study of Adverse Events' (IBEAS)

BACKGROUND

Interest in patient safety (PS) is growing exponentially, fuelled by epidemiological research unveiling the extent of unsafe care. However, there is little information about the frequency of harm in developing and transitional countries. To address this issue, the authors performed a study known as the Iberoamerican Adverse Event Study, through a collaborative between the governments of Argentina, Colombia, Costa Rica, Mexico and Peru, the Spanish Ministry of Health, Social Policy and Equality, the Pan American Health Organization and the WHO Patient Safety.

METHODS

The study used a cross-sectional design, involving 58 hospitals in the five Latin American countries, to measure the point prevalence of patients presenting an adverse event (AE) on the day of observation. All inpatients at the time of the study were included.

RESULTS

A total of 11 379 inpatients were surveyed. Of these, 1191 had at least one AE that the reviewer judged to be related to the care received rather than to the underlying conditions. The estimated point prevalence rate was 10.5% (95% CI 9.91 to 11.04), with more than 28% of AE causing disability and another 6% associated with the death of the patient. Almost 60% of AE were considered preventable.

CONCLUSIONS

The high rate of prevalent AE found suggests that PS may represent an important public-health issue in the participating hospitals. While new studies may be needed to confirm these results, these may already be useful to inspire new PS-improvement policies in those settings.

Incidence of adverse events related to health care in Spain: results of the Spanish National Study of Adverse Events

OBJECTIVE

To determine the incidence and incidence density of adverse events (AEs) in Spanish hospitals (including the pre-hospitalisation period).

METHOD

Retrospective cohort study.

RESULTS

The incidence of patients with AEs relating directly to hospital care was 8.4% (95% CI 7.7% to 9.1%) and rose 9.3% (95% CI 8.6% to 10.1%), including those from the pre-hospitalisation period. The incidence density was 1.2 AEs per 100 patient-days (95% CI 1.1 to 1.3). The incidence of moderate and serious AEs was 5.6 AEs per 1000 patient-days (95% CI 4.9% to 6.3%). In 66.3% of AEs, additional procedures were required and in 69.9% additional treatments were required. In total 42.8% of AEs were considered as avoidable. Of the subjects with some intrinsic risk factors, 13.2% developed AEs compared with 5.2% of the subjects who had no risk factors (p<0.001), and 9.5% of the subjects who had some extrinsic risk factors developed AEs compared with 3.4% of the subjects who had not (p<0.001). Patients older than 65 years of age showed a higher frequency of AEs than those under this age (12.4% vs 5.4%, p<0.001, RR 2.5). The most frequent AEs were those associated with medication (37.4%), hospital infections of any type (25.3%) and those relating to technical problems during a procedure (25.0%). A total of 31.4% of the AEs involved an increase in the length of stay. The AEs associated with medical assistance caused 6.1 additional hospital stays by patient.

CONCLUSIONS

The incidence of patients with AE related to medical assistance in Spanish hospitals was relevant and similar to those found in the studies from Canada and New Zealand that had been conducted with comparable methodology. Patient vulnerability has been identified therein as playing a major role in generating healthcare-related AEs. These and other recent results indicate the need for AEs to be considered a public health priority in Europe.