El costo real de la prevención farmacológica de la enfermedad en el marco de ensayos clínicos de eficacia y efectividad

9 05 2011

Järvinen TL, Sievänen H, Kannus P, Jokihaara J, Khan KM. The true cost of pharmacological disease prevention.  BMJ. 2011;342:d2175. doi: 10.1136/bmj.d2175.

Es errado asumir que cuando una intervención es eficaz puede ser aplicada ampliamente en la práctica clínica.

Existen factores que influyen en que un tratamiento en la comunidad sea exitoso luego de que su eficacia ha sido demostrada: los pacientes,  la exactitud del diagnóstico, la adherencia,  acceso a los servicios de salud entre otros y es considerando estos factores en el marco de ensayos clínicos de efectividad que se debe realizar el análisis de costo-efectividad  de una  intervención.

Descargar el artículo completo aquí.





Sesgos en estudios clínicos que utilizan placebo.

5 05 2011

Placebo effect studies are susceptible to response bias and to other types of biases.

J Clin Epidemiol. 2011 Apr 23  

Si te interesa el artículo completo me escribes a dpcuesta@hotmail.com y te lo envio.

OBJECTIVE: Investigations of the effect of placebo are often challenging to conduct and interpret. The history of placebo shows that assessment of its clinical significance has a real potential to be biased. We analyze and discuss typical types of bias in studies on placebo.

STUDY DESIGN AND SETTING: A methodological analysis and discussion.

RESULTS: The inherent nonblinded comparison between placebo and no-treatment is the best research design we have in estimating effects of placebo, both in a clinical and in an experimental setting, but the difference between placebo and no-treatment remains an approximate and fairly crude reflection of the true effect of placebo interventions. A main problem is response bias in trials with outcomes that are based on patients’ reports. Other biases involve differential co-intervention and patient dropouts, publication bias, and outcome reporting bias. Furthermore, extrapolation of results to a clinical settings are challenging because of a lack of clear identification of the causal factors in many clinical trials, and the nonclinical setting and short duration of most laboratory experiments.

CONCLUSIONS: Creative experimental efforts are needed to assess rigorously the clinical significance of placebo interventions and investigate the component elements that may contribute to the therapeutic benefit.





Los ensayos clínicos pragmáticos – Guías para una mejor atención al paciente?

5 05 2011

Ware J,  Hamel MB. Pragmatic Trials — Guides to Better Patient Care?.  N Engl J Med 2011; 364:1685-1687

Although randomized clinical trials provide essential, high-quality evidence about the benefits and harms of medical interventions, many such trials have limited relevance to clinical practice. The investigations are often framed in ways that fail to address patients’ and clinicians’ actual questions about a given treatment. For example, placebo-controlled trials of a new migraine medication help to establish its efficacy, but they may not help clinicians and patients choose between the new medication and other available treatments. Moreover, since most randomized clinical trials are efficacy trials, researchers enroll a homogeneous patient population, define treatment regimens carefully and require that they be followed assiduously, and inform neither patients nor study personnel about treatment assignments. Thus, although these trials are conducted in clinical settings, their enrolled populations and management approach don’t reflect the complexity and diversity of actual clinical practice. Because of concerns about real-world applicability and about improving the quality and value of health care, “pragmatic” or “practical” trials are attracting increasing attention.

Descargar http://www.nejm.org/doi/pdf/10.1056/NEJMp1103502