3. How do I access the evidence?

4. How do I access the evidence?

How can we access the evidence, given that it isn’t always free?

Scientific publishing is big business and so many of the key sources of information will not be free for everyone to access. It helps to be aware of the different access models.

Databases are generally just a search tool – they contain details of publications but not the full text of the publications themselves. There is therefore a two-step process to acquiring evidence via bibliographic databases:

  • getting access to databases
  • getting access to the full-text of the publications.

Many of the databases and journals needed for EBVM are not free to access. However, there are various strategies for gaining access.


A paywall is a means of restricting access to online information content to those who have paid for it.
You may find details of databases and journal articles on the internet, but then find you cannot access them because the publishers have put up a paywall. They may ask you to log in with a username or password, which will only work if a payment has been made, or they may ask for a payment there and then.

The role of libraries and librarians

One of the main roles of the modern library is to pay for subscriptions to online journals and databases so that all the members of that library can get free access. Joining a library can be a considerable support to the practice of EBVM. Librarians and information professionals support EBVM through:

  • training in literature searching
  • one-to-one support for developing a search strategy
  • help with retrieving the full text of journal articles.

See What are the best options for accessing evidence if you are a vet in practice? (Acquire 4.2) for more information.

Institutional subscriptions

Organisations without a library can buy a subscription to journals and databases for members of that organisation to access. The subscription price can vary depending on the number of people who will have access. Institutional subscriptions are used by research centres, companies, and veterinary practices.

Individual subscriptions

Individual veterinarians or researchers can buy a subscription to journals for their own personal use.


Journal publishers may offer the opportunity to purchase access to individual articles, on demand as needed. It is convenient and may save money compared to subscriptions, or prove expensive; it depends on what is purchased and how often.

Renting articles

There are services, such as Deep Dyve , that provide, in essence, the ability to rent articles. These are generally 'freemium' payment models, with searching and article abstracts representing the free portion and access to the full articles representing the premium portion.

Open access

There is a strong will among many in the scientific community to make publications open access , with free and unrestricted access online.

Many research councils are now making it obligatory for the publications arising from the research that they fund to be made available open access, and so it is likely that this trend will grow in future years. Some journals are purely open access, but some traditional journals make individual articles available as open access if the author of the article pays a publication fee.

Veterinarians can gain a lot from the open access movement – as it grows, more and more sources of evidence will become freely available to all.

We can all contribute to the open access movement by publishing our research open access whenever possible!