“Information mastery” involves the ability to identify, evaluate, and apply valid and relevant information quickly.1
It is based on the concept that information has different degrees of usefulness, and that the best information is highly valid, highly relevant, and takes little work to locate, evaluate, and understand. Validity is a matter of satisfying the criteria developed by the Evidence-Based Medicine Working Group.2
Relevant information is called “patient oriented evidence that matters” (POEMs).3
Patient oriented evidence tells clinicians, directly and without the need for extrapolation, that a diagnostic, therapeutic, or preventive procedure helps patients live longer or live better. This information matters when it requires a change in practice of a clinician.
Patient oriented evidence is contrasted with “disease oriented evidence” (DOE), which is research focusing on either intermediate or surrogate outcomes.4
Many practices in medicine are currently based on disease oriented evidence, which may later be shown to be either correct or incorrect when the patient oriented outcomes are studied. Numerous examples exist of medical practice based on disease oriented evidence that have been shown, after the publication of truly patient oriented evidence, to be not only ineffective but even harmful ().5
On the other hand, new, valid POEMs often are rejected, especially when they don't “make sense” or conflict with disease oriented evidence.
Examples where patient oriented evidence does not confirm disease oriented (surrogate) end points
Although valid POEMs are usually found in research articles, most clinicians rely on expert recommendations on which to base their clinical care.6
These recommendations are transmitted via review articles, book chapters, continuing medical education presentations, consensus conferences, and consensus guideline development.
These recommendations can be supported either by patient oriented evidence, disease oriented evidence, or some combination of preliminary research findings augmented with expert opinion. We sought to measure the accuracy of one mode of information dissemination by evaluating how experts represented the results of the United Kingdom prospective diabetes study (UKPDS).7-10
We choose this study and the transmission of its results for several reasons. Other than the university group diabetes project, it is the only large study of patients with type 2 diabetes of new onset to evaluate the effect of intensive blood glucose control on long term mortality. As such, it presents vital information that should be used to guide patient care. Also, it is a useful study for our purposes because it contains both patient oriented outcomes that are valuable to clinicians as well as several outcomes that are disease oriented and thus have less immediate clinical application.
The United Kingdom prospective diabetes study (UKPDS)
Started in 1977, the UKPDS was designed to determine whether tight glycaemic control decreases diabetes related complications and increases life expectancy. A sub-study within the main study investigated whether tighter control of blood pressure in patients with hypertension decreased complications.
The investigators enrolled about 4000 patients with type 2 diabetes of new onset. These patients were assigned to receive either conventional or more intensive treatment and were monitored for a median of 10.7 years for long term effects. Conventional treatment aimed to maintain fasting plasma glucose readings below 15 mmol/l (270 mg/dl), whereas intensive treatment aimed for “tight” control of less than 6 mmol/l (110 mg/dl). Half of the patients receiving intensive treatment, mostly non-overweight patients, reached this goal. lists the major outcomes of the UKPDS.7-11
Outcomes of the United Kingdom prospective diabetes study (UKPDS) and their subsequent reporting in 35 review articles on treatment of type 2 diabetes
The UKPDS provided several outcomes that can be categorised as POEMs (). Attempting to achieve tight blood glucose control did not prevent premature mortality. However, regardless of their level of blood glucose control, overweight patients receiving metformin had significantly fewer diabetes related outcomes, and fewer died because of diabetes or other causes. The effect on outcomes of tight blood pressure control (<150/<85 mm Hg) were more impressive than tight blood glucose control: in addition to lowering the risk of aggregate complications, good blood pressure control also decreased mortality.
The study also evaluated the effect of blood glucose control on disease oriented outcomes. Tight control of blood glucose decreased the aggregate risk of 21 different complications, although most of this benefit was due to changes in intermediate outcomes. For example, the need for photocoagulation was diminished, although rates of vision loss were not affected. Changes in serum creatinine levels were less, though the likelihood of developing end stage renal disease was not affected.