ACCESSSS is a service to help provide current best evidence for clinical decisions. It conducts searches simultaneously in several evidence-based information services (online evidence-based texts, evidence-based guidelines and pre-appraised journal publications). ACCESSSS also provides email alerts to newly published evidence in the user’s chosen area(s) of training/interest.

Searching ACCESSSS yields content that is hierarchically organized: Always look first at the content available at the highest level of the hierarchy, as it is most likely to be useful for clinical purposes.

Evidence at all levels of the pyramid has been pre-appraised for scientific merit and clinical relevance. The levels of the pyramid reflect the extent to which the evidence has been integrated into the context of decisions for clinical care, with the most integration at the top.

  • Systems provide patient-specific, evidence-based, computerized decision support at the point of care – many systems are "under construction" at present
  • Summary Clinical Texts provide the best summarization of evidence for clinical decisions for entire clinical topics (eg, asthma, diabetes)
  • Systematic Guidelines provide evidence-based recommendations for clinical care for specific aspects of topics (eg treatment of hypertension in the elderly)
  • Systematic Reviews are detailed and exhaustive summaries of evidence on a specific clinical question (eg, effectiveness of interventions to enhance patient adherence to prescribed medications)
  • Studies are original investigations into the diagnosis, treatment, prognosis, prediction, and prevention of specific clinical disorders (eg, a randomized trial of a new vaccine for preventing Zika virus infection)

For more details please consult: Explanation of the EBHC Pyramid 5.0

What is McMaster PLUS and what do its clinical ratings mean?

Journal articles below the level of "Summary Clinical Texts" (see What is ACCESSSS? above) are selected from over 120 clinical journals through a systematic process of critical appraisal by expert research staff (using these criteria) and ratings of qualifying articles by 3 front-line clinicians from a panel of over 3500 physicians around the world (using these scales for clinical relevance and newsworthiness), creating the McMaster Premium Literature Service (McMasterPLUS™). Articles are processed very quickly after online publication and posted before it is likely that they could be incorporated into higher levels (ie "Summary Clinical Texts" and Systematic Guidelines).

McMaster PLUS features include:
  • E-mail alerts about new evidence, tailored to the user's interest profile and adjustable for their time demands. Each alert includes MORE clinical ratings and comments, and electronic links to the article's abstract via PubMed (if available).
  • Links to fulltext articles and summaries for free fulltext articles and DynaMed topics (a subscription or fee may be needed for some of these articles and summaries).
  • A cumulative searchable database of the alerts that is continuously updated (from 2003 forward).
  • Personalized alert settings allowing each user to register their health care interests, leading to matching of those interests to the appropriate "virtual" subset of the accumulating database.
  • Hit Parade, the articles most frequently accessed in PLUS in the past 90 days.

Where can ACCESSSS be used?


ACCESSSS and its associated resources are available for use anywhere on campus and local hospitals. Simply login directly at / and begin searching.


ACCESSSS can be accessed from off-campus, but a number of its associated full-text resources (especially at the higher levels) require that you log in to your local proxy. To save you time, proxies have been integrated into the result links for institutions which have signed up for ACCESSSS.


Great resource, convenient to use and up to date. I subscribe to a number of search or newsletter services and this is by far the best. I highly recommend it to others.

McMaster Faculty

...the greatest innovation since PubMed.

McMaster Faculty

... a fantastic teaching tool.

...Definitely an EBM tool of the future that will likely have a great impact on the way we access the evidence.

Faculty outside McMaster

The Knowledge Refinery processes the raw material into products to be utilized by the consumer. Now I understand why you call it a Refinery. When oil was first discovered, they mainly used it for lighting, which was very important, but then someone discovered how to refine it into the petroleum products which now shape the world's economy. Fascinating parallels!


ACCESSSS is useful when someone does a systematic review, when someone needs not only a quick answer but also wants to do a more in-depth review. When I used the same search strategy in PubMed, I spent at least 15 minutes and got lots of results a lot of which were not very relevant so I had to go through them one by one whereas ACCESSSS gave me exactly what I wanted within seconds!

Visiting Clinical Scholar

This is a fabulous resource. It cuts my searching time significantly.
Registered Nurse