This release about the ability of grip strength testing to predict death and disease rates leaves readers without enough context and ultimately overstates the importance of the findings. While the tone of the release is measured and the quotes include some caution about interpreting the results, there’s no mention anywhere in the release about the limits of observational studies — which are discussed both in the study that’s the basis for the release and the accompanying editorial. And although overall death rates are unquestionably an important outcome, the release does not tell readers what it would mean for a person to be identified as having a 17 percent higher risk. What use is that information and how would it affect how that person is cared for?
“Why This Matters” is something this news release should have educated us about. A clinical test result is useful only when it helps people make decisions. This release should have spent more time addressing how the study results might be applied. Would identifying a person as being at a 17 percent increased risk of death or a 7 percent increased risk of a heart attack change how doctors would monitor or treat him or her? Would someone be prescribed a statin based on a finding of decreased hand grip strength? Even though the study was intended only to assess how grip test results in a wider variety of countries compare to previous findings in high-income countries, the release could have at least briefly mentioned how such test results are commonly used in clinical settings.
What’s more, it’s clear that news coverage, feeding off this news release, is reporting on this without caveats about observational studies, and therefore, delivering an incomplete message to the public. And it all started with this news release, because the caveats appear in both the journal article and in an accompanying commentary. Here are a handful of examples:
The release says that grip strength is low-cost, but a dynamometer is not something used routinely in clinical practice. Why not provide a cost estimate for both the dynamometers, the cost of administering the test in the clinical setting, and the cost of potential widespread risk-stratifying use? Would this still be low-cost? Maybe so, but some projections are possible IF you deal with real numbers, not just the researchers’ value judgment that it is “low-cost.”
The release does not tell readers how important a 7 to 17 percent increase in risk for the measured outcomes really is. There are no absolute figures included, only relative risks. What’s more, the release makes no mention of how this sort of risk stratification would be used. Would people identified as having a 10-20 percent higher risk of certain conditions be offered different tests or treatments than those with stronger grips? Without this sort of context, readers of this release don’t have any way of knowing what the benefits of grip testing might be.
It is also odd that the headline and lead paragraph of the release highlighted heart attack and stroke, when the risk stratifications for those events were smaller than those for other outcomes.
As mentioned in the section on benefits, the release does not explain how the test results might be used. If the intent is to steer people identified as being at higher risk toward more testing or treatment, then the release should have mentioned the risk of doing more harm through overtreatment.
The release would have been better if it had included a clear statement near the top highlighting that this observational study cannot say whether poor grip strength itself predisposes a person to health problems or is merely a result of factors that also lead to health problems. The journal article included that caveat: “The observational nature of this study does not allow us to make strong conclusions on the causal role of muscular strength in death or cardiovascular disease. Although we adjusted for many potential confounders, we cannot exclude the possibility that residual confounding underlies the associations between grip strength and these outcomes.” And an accompanying editorial also described “the limitations of observational epidemiology to address causal pathways.” Yet the Lancet news release made no mention of these clearly-stated limitations. Journal news releases could do a great deal to help educate journalists and the public about the value of, and the limitations of, such research.
The outcomes highlighted in the release, including overall death rates and cardiovascular disease, are indeed important, as is evidence on ways of improving clinical practice. But we’re troubled by the introduction of the concept of hand grip strength being a “new biomarker of aging” — as if aging were some type of disease that we need better tools to diagnose and/or monitor. We’ll rule it Satisfactory with some reservations.
This rating is for a sin of omission. It does not appear that any conflicts were hidden, but all news releases should routinely report a summary of funding sources and disclosures.
The journal article reports funding sources for the study and lead authors. There are no competing interests reported. The maker of the dynamometer used does not appear to have played any role in the study. But even in cases like this, where it does not appear that there any funding or other conflicts of interest, news releases should routinely include some reference to funding and disclosures by researchers.
The release specifically notes that grip strength results are a stronger predictor of death than systolic blood pressure. But what about the most common ways that clinicians currently assess the health risks of patients, such as with Framingham data and the related NHLBI heart risk assessment tool — free and online? Call us picky, but we can easily recall widespread news coverage of whether wrinkles in your earlobes can predict heart attack risk. So we don’t think it’s unreasonable to expect some reference to an enduring, well-supported alternative to the risk predictor of the day.
The release implies that the type of dynamometer used to assess grip strength in this study is widely available, but a clearer statement about availability, especially in low-income countries, would have made the release better.
The release notes that this association between grip strength and health risks has been documented previously in high-income countries, and that a key feature of this study is the inclusion of people from low- and middle-income countries.
This is a close call. The tone of the release is generally measured. However, the release headline suggests that hand grip strength is “simple” and “low cost” — neither of which have been proven in widespread clinical practice. It takes training to use this device and interpret the results correctly. And it’s not clear how accurate this test is or if it’ll lead to unnecessary tests or treatments. In other words, the release conveys a certainty about this test that just doesn’t exist — something we think is unjustified.