Prozac shows promise in recovery from stroke

Does the story adequately quantify the benefits of the treatment/test/product/procedure?

Not Satisfactory

The story cites the absolute improvements on motor skill test scores.

But these numbers are unanchored from context. All we know is that it was the score on a test of motor skills. We don’t know the measurement, the scale, or baseline values. So the numbers have no meaning for readers. It’s as if I told you “my running speed has increased by 10.” The lack of a baseline score is particularly relevant in this story because, as it turns out, the group receiving fluoxetine started with slightly more severe problems than the control group. Although the difference was not reported to be statistically significant, any difference in baselines scores for the primary outcome may reflect a flaw in how the study randomized people.

Second, none of the “positive effects” of the drug mentioned are challenged. In light of the preliminary nature of the study, these apparent benefits are not conclusions, they’re open questions. That perspective is missing, misaligning the tone of the piece.

Please see some related comments under Quality of Evidence.

Does the story adequately explain/quantify the harms of the intervention?

Not Satisfactory

Generally this isn’t a risky medicine, but we ding the story here for not only failing to quantify harms, but perhaps mischaracterizing the safety data from the study. It quotes the researchers as stating that side effects were rare and mild. But in the actual study, 25% of those taking fluoxetine had transient digestive problems (compared to 11% receiving placebo), and there were two serious side effects, a partial seizure and a serious case of low sodium. A more accurate summary would’ve been the softer statement that MOST side effects were rare OR mild.

Does the story seem to grasp the quality of the evidence?

Not Satisfactory

There are good points in here about the treatment regimen, number of patients, follow-up period, years of the study, and its peer-reviewed status. Evaluation of the evidence, however, was absent.

The only caveat provided was that “more research is needed to see if the effects continue over time.” You wouldn’t know from that line, or the rest of the article’s tone, that this study was preliminary. No evaluation was provided to counter the enormous potential from “experts,” who wonder if Prozac should be given to “most stroke patients with motor skill problems.”

But the word potential means unconfirmed, unrealized, uNPRoven. Promise has a flipside. What was the flipside of this early research’s promise? Here are the reasons for caution cited by the researchers themselves:

• A study with 118 subjects is too small to draw conclusions. [We shouldn’t be surprised if an identical study in 118 different people had different results. Even if it’s the largest such study to date, and all previous studies were small, that doesn’t make this study large enough.]
• A 3-month follow-up period is too short. [We don’t know if the benefit is temporary.]
• The subjects “did not represent the general population of stroke patients.” [The study excluded people with certain types of impairments and disabilities. Early studies often enroll people with very specific characteristics, and when they later open the gates to a broader group of subjects, with a realistic blend (mess) of characteristics, the results can be different.]

The authors conclude that their results need to be confirmed in larger trials that can better rule out random noise in the data, enroll people more similar to the general population, track them for longer, and use a primary measurement that’s more relevant to patients’ function. The magnitude of this simple treatment is impressive, and if validated in such other studies, the result would indeed be ground-breaking. But until then, one should be cautious.

The article also didn’t evaluate the trial’s features that enhanced its quality, such as the double-blinding, randomization process, and multicenter setting.

Does the story commit disease-mongering?

Not Satisfactory

This is one of the areas where this story could have been a lot clearer by explaining the study population with more detail than just “people who just had a stroke.” It was people who had the more common type of stroke, ischemic stroke, leading to a specific type of motor deficit.

Patients enrolled in this study had profound weakness due to a stroke, and these results may be generalizable to that population. But many patients have milder and even more severe stroke symptoms. It is uncertain whether these results would apply to lesser or more severely affected patients. By not saying these results only apply to a certain subset of stroke patients, the story implies that this is a good treatment for any patient with motor weakness after a stroke. That implication would widely overstep the findings reported in this study.

In addition, the study itself doesn’t say how many patients were screened to enroll the 118 patients. In other words, it doesn’t describe how much the general population was filtered. That information would give a clue to how small this subpopulation really is out there in the real world.

Does the story compare the new approach with existing alternatives?

Not Satisfactory

Again, the story reported only what was in the study but fell short on context. It notes that all subjects in the study received physiotherapy, which means Prozac was compared to physiotherapy alone. But it didn’t describe the established medications routinely used in patients after a stroke, thereby making Prozac and SSRIs were the only drugs to be considered.