The Decrease of Reported Effectiveness in Medical Trials
Author Information
Author(s): Gehr Bernhard T, Weiss Christel, Porzsolt Franz
Hypothesis
The reported effect size of medical therapies decreases over time.
Conclusion
The effectiveness of medical therapies reported in RCTs decreases over time in three of the four investigated pharmaceuticals, mainly due to baseline differences.
Supporting Evidence
- The reported effect size of Pravastatin decreased by 3.22% LDL-C every five years.
- Timolol's reported effect size decreased by 0.56 mmHg every five years.
- Latanoprost's reported effect size decreased by 1.78 mmHg every five years.
- Atorvastatin showed no significant change in reported effectiveness over time.
Takeaway
When doctors test new medicines, they often find that the medicines seem to work better at first, but over time, the results show they might not be as effective as originally thought.
Methodology
A meta-analysis of randomized controlled trials was conducted, focusing on the effect sizes of four pharmaceuticals over time.
Potential Biases
Potential publication bias and time of publication bias may affect the reported effectiveness.
Limitations
The study did not explore other potential factors influencing the decrease in reported effectiveness.
Participant Demographics
The study included various patient populations across the trials, but specific demographics were not detailed.
Statistical Information
P-Value
P < .0001 for Pravastatin and Timolol; P = .0074 for Latanoprost; P = .8618 for Atorvastatin.
Confidence Interval
95% CI: (-4.50/-1.93) for Pravastatin; (-0.79/-0.34) for Timolol; (-3.04/-0.51) for Latanoprost.
Statistical Significance
p<0.0001
Digital Object Identifier (DOI)
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