This week's BMJ is almost like a reminder of first principles in science and medicine.
Firstly, Niell Adhikari and colleagues confirm that in critical care medicine, theoretical hypotheses dont always translate into clinical and practical results. They review the use of Nitric Oxide in acute ling injury and show that depsite the physiological improvements it does not decrease death and conversely causes renal injury,limiting its use for this indication.
So, not everything that is supposed to work - works!
The second article is an incredible, much required review discussing the effect of interventions to improve drinking water on diarrheal diseases. As if to reinforce a point the authors from the London School show that any intervention will reduce the incidence of diarrhea. This review simply goes to show that simple measures are always the best and sanitation the key to all our problems and the most important medical advance over the last 166 years!
Finally, science is complicated enough for us not to make it more complicated with sophisticated biostatistics and data difficult to interpret. This review suggests that use of composite end points in cardiovascular trial points used mainly to decrease sample size might be fraught with its own problems and may lead to data being interpreted the wrong way.
So, when you read an article be careful, be careful when trying to transfer physiological phenomenon to the clinic and stick to the simple interventions - Clean Water!
Sunday, 15 April 2007
NEJM -- April 12,2007
New therapies to tackle type -2 diabetes is always a big industry. This week's NEJM publishes a clinical trial using a Interleukin-1 antagonist to improve glycaemic control in DM. Insulin production is increased, beta cell secretory functions are improved and there are very few side effects provided you were willing to inject the drug every day for 13 weeks. Hopefully, further studies might improve the dosing characteristics and lengthen the half life of the drug. If you are a diabetic and wait for a few more years, you might not have to inject insulin anymore, just a IL-1 antagonist.
If you know of patients paying a lot of money in private hospitals after a heart attack to get an operation to put a stent into them,let them know that its not always necessary. More importantly, let the doctors know to have a look at this paper involving over 2000 patients with stable coronary artery disease where percutaneous coronary intervention(PCI) + medical therapy did not have any added benefit over treating such patients by optimal medical therapy alone.
If you know of patients paying a lot of money in private hospitals after a heart attack to get an operation to put a stent into them,let them know that its not always necessary. More importantly, let the doctors know to have a look at this paper involving over 2000 patients with stable coronary artery disease where percutaneous coronary intervention(PCI) + medical therapy did not have any added benefit over treating such patients by optimal medical therapy alone.
NEJM -- April 12,2007
When we eradicate the world of wild poliovirus and start immunising with injectable polio virus(IPV) instead of Oral Polio Vaccine (OPV), will IPV actually be useful? This study is the first field study to evaluate the efficacy of IPV after eliminating the confounding factors of OPV use and wild type poliovirus infection.
I find this entire area of public health fascinating. Unfortunately for me I was born after global smallpox eradication( I never got a shot) and polio affords me an opportunity to follow the eradication of a disease in real time. I remember giving OPV drops to kids on National Immunisation days while in college but this study addresses a far more important issue.
The WHO in 2004 published a report suggesting the use of IPV following global eradication of polio and the last detectable case of Vaccine-derived poliovirus (VDPV). This is a major policy decision that has to be made and policy and guidelines are being developed since 1998 when the first meeting to discuss post-eradication scenarios took place.
The fundamental issue pertains to the use of any polio vaccine once eradication occurs. The reason OPV is not favoured is because of its propensity to cause VDPV strains which cause poliomyelitis and its ability to spread like wild type poliovirus. So, we use IPV,yes? Not yet, because we dont have enough data about what kind of regimens are efficacious or whether it can prevent an outbreak of wildtype poliovirus. The Cuban study addresses this issue by evaluating IPV efficacy against a challenge of OPV in a setting of 0% prevalence of poliovirus.
The study shows that IPV induces antibodies against the three serotypes of poliovirus but maternal antibodies (induced by OPV vaccination) may decrease protection to poliovirus serotype 2. It also challenges the notion that IPV prevents the excretion of poliovirus and shows that previous data which postulated IPV being as efficacious as OPV might have been influenced by contamination of subjects with either OPV or wild type poliovirus.
What is quite interesting is that although the data suggests that perhaps IPV might not prevent the excretion of poliovirus in stool, it might decrease the amount of poliovirus excreted.
But, lets be realistic about the results. As far as clinical trials for this study is concerned Cuba is a ideal situation and not really representative of countries like India where wild type poliovirus is more prevalent and possibly of higher virulence and therefore the study authors finally suggest careful consideration based on scientific evidence before we blindly substitute OPV for IPV in tropical countries endemic for poliovirus.
If you are interested in this topic also read this Science paper which tackles post-eradication era policies.
I find this entire area of public health fascinating. Unfortunately for me I was born after global smallpox eradication( I never got a shot) and polio affords me an opportunity to follow the eradication of a disease in real time. I remember giving OPV drops to kids on National Immunisation days while in college but this study addresses a far more important issue.
The WHO in 2004 published a report suggesting the use of IPV following global eradication of polio and the last detectable case of Vaccine-derived poliovirus (VDPV). This is a major policy decision that has to be made and policy and guidelines are being developed since 1998 when the first meeting to discuss post-eradication scenarios took place.
The fundamental issue pertains to the use of any polio vaccine once eradication occurs. The reason OPV is not favoured is because of its propensity to cause VDPV strains which cause poliomyelitis and its ability to spread like wild type poliovirus. So, we use IPV,yes? Not yet, because we dont have enough data about what kind of regimens are efficacious or whether it can prevent an outbreak of wildtype poliovirus. The Cuban study addresses this issue by evaluating IPV efficacy against a challenge of OPV in a setting of 0% prevalence of poliovirus.
The study shows that IPV induces antibodies against the three serotypes of poliovirus but maternal antibodies (induced by OPV vaccination) may decrease protection to poliovirus serotype 2. It also challenges the notion that IPV prevents the excretion of poliovirus and shows that previous data which postulated IPV being as efficacious as OPV might have been influenced by contamination of subjects with either OPV or wild type poliovirus.
What is quite interesting is that although the data suggests that perhaps IPV might not prevent the excretion of poliovirus in stool, it might decrease the amount of poliovirus excreted.
But, lets be realistic about the results. As far as clinical trials for this study is concerned Cuba is a ideal situation and not really representative of countries like India where wild type poliovirus is more prevalent and possibly of higher virulence and therefore the study authors finally suggest careful consideration based on scientific evidence before we blindly substitute OPV for IPV in tropical countries endemic for poliovirus.
If you are interested in this topic also read this Science paper which tackles post-eradication era policies.
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