Commentary

Sahaya Josephine takes you through this paper and explains the implications

The paper addresses two important issues, one being uptake of vaccination for influenza and the other being informed consent. Increasing vaccine uptake rates is a top priority in the effort to prevent winter crises.

Why was it done?

The authors set out to find out what types of consent procedures were in place for influenza vaccination in Dutch nursing homes and what effect it had on the overall uptake rates.

How was it done?

This was a postal survey of nursing home physicians done in a set period or at one point in time and so is called a cross sectional or prevalence study. The authors wished to obtain a snapshot of the vaccination rates and consent policies. A postal questionnaire is usually considered to be a simple and convenient method for collecting this type of information. The information was collected to discover whether deviation from standard informed consent procedures was justified.

The questionnaires were sent to all nursing homes in the Netherlands and therefore this was an all inclusive approach avoiding any selection bias. Selection bias would normally occur if the sample selected was not representative of the nursing home population.

The authors requested nursing home physicians to provide exact vaccination rates or close estimates. An element of information bias or observer bias could be possible, as it is not clear if there was a standard method of collecting data in all the nursing homes.

What did they find?

The survey had a response rate of about 73%, which is reasonable considering the difficulties in conducting a survey. The response rate could have been better if the non-responders had been sent a reminder or contacted by telephone. As more than 25% of the homes did not respond, this could have a significant effect on the overall results. Nursing homes that do not have explicit policies may have failed to respond. Also, where there were problems or complications in homes due to inadequate vaccination rates, there may have been a poor response or no response.

There is no information on what proportion of nursing homes provided exact rates and how many provided only estimates. The estimates were within 10% ranges and it is not known if the number of nursing homes providing estimates was substantially higher. This could also have an effect on the apparent differences noted between the homes using different consent policies.

The authors conclude that homes that use tacit consent have higher vaccination rates. This was statistically significant, with a P value of <0.001. This means that the difference in the uptake rates may be attributable to a tacit consent policy. But is this sufficient justification for introducing such a policy? The authors themselves agree it is not.

It is essential to distinguish between what is statistically significant and clinically significant. Ideally it would have been more useful to know the clinical effects of inadequate vaccination rates before reaching a conclusion about what type of consent procedure is justified. However, this is not something which can be measured easily or accurately, and another type of study would be required. The authors rightly point out that other issues like vaccinating healthcare staff are also important to achieve good herd immunity.

In the United Kingdom, although uptake of influenza vaccine is increasing, there are instances when individuals in high risk groups may not be vaccinated. The single most important factor in patients accepting influenza immunisation is that their doctor recommends they have it. The Department of Healths reference guide to consent for examination or treatment states that it is a general legal and ethical principle that valid consent must be obtained before starting treatment or physical investigation, or providing personal care for a patient.¹ The consent needs to be given voluntarily by an appropriately informed person.

In general practice, if an individual attends a clinic for vaccination, that could be considered as giving implied consent. The nursing home setting is different, and many patients may not have the mental capacity to make an informed choice. In such instances, for both ethical and legal purposes it is essential that explicit written policies are in place to guide the staff. Therefore, using a tacit consent policy may not be the preferred alternative. This study emphasises that the debate on consent issues is vital and that it is something that all healthcare professionals need to be well informed about at all stages of their career.

1. Department of Health. Reference guide to consent for examination or treatment. London: DoH, 2001.