It’s rare to see researchers say flat-out that an experimental result leaves them uncertain. There seems to be such a temptation to either declare victory with statistical significance (setting the significance level to 0.1 if necessary to clear the bar) or to claim that weak and noisy results are “suggestive” or, conversely, to declare non-significance as evidence of no effect.
But . . . hey! . . . check this out:
Under the heading, “The one med paper in existence that was somewhat ok with uncertainty?,” Zad points to this article, “Randomized Trial of Nocturnal Oxygen in Chronic Obstructive Pulmonary Disease,” by Yves Lacasse in the New England Journal of Medicine:
Abstract Conclusions: “Our underpowered trial provides no indication that nocturnal oxygen has a positive or negative effect on survival or progression to long-term”
Full-text Discussion: “Our trial did not show evidence of an effect of nocturnal oxygen therapy on survival or progression to long-term oxygen therapy in patients with COPD with isolated nocturnal oxygen desaturation. Because enrollment in the trial was stopped before we had reached our proposed sample size, the trial was underpowered, with the consequence of a wide confidence interval around the point estimate of the absolute difference in risk between the trial groups at 3 years of follow-up. The data that were accrued could not rule out benefit or harm from nocturnal oxygen and included the minimal clinically important difference determined before the trial. However, nocturnal oxygen had no observed effect on secondary oucomes, including exacerbation and hospitalization rates and quality of life. Furthermore, the duration of exposure to nocturnal oxygen did not modify the overall effect of therapy. Because our trial did not reach full enrollment, it makes sense to view our results in the context of other results in the field. A systematic review of the effect of home oxygen therapy in patients with COPD with isolated nocturnal desaturation identified two published trials that examined the effect of nocturnal oxygen on survival and progression to long-term oxygen therapy.”
Progress!