This news release reports on new results from an on-going and major clinical trial — the SPRINT (Systolic Blood Pressure Intervention Trial) — that compared the outcomes of two groups of elderly hypertensive people given different systolic blood pressure goals — 140 mm of mercury versus 120 mm of mercury. And while it does report that the clinical outcome for those in the lower target group was better than that of the higher target group, the release (from the National Institutes of Health [NIH] section dealing with heart and lung disease) gives scant details that might help readers apply the results to their own situations.
The omissions mirror problems we’ve seen in previous NIH press communications about the SPRINT study, which we’ve called attention to repeatedly on our blog:
The public has gotten conflicting recommendations on what the optimum goal for blood pressure treatment should be for seniors. The recommendations range from 140 mm Hg for adults to 150 mm Hg for adults aged 60 and up, and to 160 mm Hg for people over 80.
The release states that, “About three-fourths of the U.S. population aged 75 and older live with hypertension, a leading contributor to cardiovascular disease and death,” which certainly argues for the importance of any strategy that can mitigate this condition. If changing either a medication or its dosage can bring about a better clinical outcome, then surely that is important.
The release makes no mention of costs associated with the differing strategies. It states that hypertensive elderly patients receive medication to lower their systolic blood pressure to either 140 mm of mercury or 120 mm of mercury, and that, on average, the patients who had a lower targeted blood pressure required an added medication. But no specific drugs are mentioned, so readers cannot judge whether there would be cost differences between this recommended regimen and their current therapy.
The release points out that those study participants whose blood pressure goal was 120 mm of mercury had 33 percent fewer cardiovascular events, such as heart attacks or heart failure, and had a 32 percent reduction in the risk of death, compared to those participants with a higher goal. Based on this, it recommends that people 75 and older benefit from a lower systolic blood pressure.
But these numbers don’t tell the whole story. It should be noted that these relative reductions correspond with absolute risk reductions of only about 0.8 to 1.3 percentage points — reflecting a number needed to treat (NNT) of roughly 100. In other words, approximately 100 people need to be treated to this target in order for 1 person to experience an improved outcome. The other 99 don’t benefit but have the potential to experience adverse effects.
The release makes no mention of the possible adverse reactions to medications that lower blood pressure, although these are widely known. Nor does the release mention any adverse reactions among the study participants other than those that were used as endpoints for the study — myocardial infarctions, strokes and heart failure, for example.
The published research article notes that while treatment carried risk of side effects for both patient groups studied, the differences between the serious side effects (low blood pressure, fainting, acute kidney injury) encountered in each group weren’t significantly significant.
Another issue not addressed in the release is that these patients were followed very closely by study staff and were examined initially every 3 months. In clinical practice, patients are often not seen that frequently which means that some patients might not get the level of monitoring needed to prevent or treat emerging complications.
We were pleased to see that the release cautioned patients to “talk to their doctor to determine whether this lower goal is best for their individual care.”
The release provides data on the number of participants, their general age and whether their targeted systolic blood pressure targets were 120 mm of mercury or 140 mm of mercury. It also states the clinical outcomes comparing the two targeted groups. While additional information would have been helpful for readers, the amount given is just barely sufficient for readers to see the benefits of the research.
One of the limitations of the study not mentioned in the release is that the study was stopped early; the subjects in the trial were followed for only 3 years. A majority of hypertensive patients will require lifetime medications, so the long-term benefits and harms of intensive therapy remain unknown.
The release does not appear to commit disease-mongering.
While this release does identify the main funding sources for the trial, it fails to mention any potential conflicts of interest, even though the paper itself discloses that three of the authors had numerous financial links to pharmaceutical firms.
Again, the release explains a trial which presumably used different medications and/or different doses to reach the targeted systolic blood pressure levels (although none are identified). It offers no information on alternative mechanisms for reaching those goals and without more information on what approaches were used, it would be hard to cite alternatives.
Without naming the drugs used in the study, the release leaves us to assume the ready availability of any of the medications. It would have been easy for the news release to indicate that the study did not use any investigational agents — just widely available blood pressure medicines. Unfortunately, the release doesn’t explain that, thus netting an unsatisfactory rating.
The release doesn’t claim novelty. Instead, it makes it clear that the latest results reinforce earlier findings about blood pressure management and stresses that the latest results are “reporting additional details about a widely-publicized study.”
The release does not appear to use any unjustifiable language. We also were glad to see that patients are cautioned to discuss — not request — this treatment approach with their doctors.