Changes

Posted: Tuesday, March 6, 2012 | Posted by Debajyoti Datta | 0 comments

In the next few days I will be migrating the blog from blogger to wordpress.

Book review: Building BrainPower

Posted: Friday, December 30, 2011 | Posted by Debajyoti Datta | Labels: 0 comments

I have got a copy of Dilip Mukerjea’s Building BrainPower: Turning Grey Matter into Gold as part of the BlogAdda book reviews program.

Lets start with the basics first – the book has been published by Westland, paperback, 314 pages and the marked price is Rs. 750. The paper and print quality is pretty good and I’m quite satisfied with the binding of the book, a necessity as the book is designed as a tool to be used and practiced. The author Dilip Mukerjea is the owner and Managing Director of Buzan Centre, Singapore.

The book is divided into five sections – the first section is about our brain – it’s a very good non-technical description covering evolution, neuroscience and a touch of neuroanatomy. The second part is devoted about the technique of Mind Mapping where the author shows you how to create and use an interconnected map of imagery and words to form a broad understanding and lasting impression about any topic. Here is the Wikipedia description of Mind Maps
“A mind map is a diagram used to represent words, ideas, tasks, or other items linked to and arranged around a central key word or idea…Mind maps are used to generate, visualize, structure, and classify ideas, and as an aid to studying and organizing information, solving problems, making decisions, and writing.”

The best part about this is the hands on approach taken by the author. He lays out the principles at the beginning and then guides the reader through numerous examples. There are many examples of Mind Maps scattered throughout the book to help the beginner get an idea. The author advocates the use of plain paper while making Mind Maps but you can use software like FreeMind to prepare your mind maps.

The third part of the book deals with communication. There are numerous tables on different methods of communication – for example the sign language. This is followed by a section containing puzzles and their solutions, quite a few to keep the reader occupied.  The last section is titled “Additional thoughts” that contains a few more interesting facts and Mind Maps thrown in.

The Impression: The approach of the book – learning by doing, is quite good. The reader wouldn’t have any problem in following the author’s instructions. There are adequate problems to practice on. The first part describing the brain is a very good read. The use of colour in the Mind Maps and the level of detail the author delves into is commendable. For example, the author devotes 16 pages to guide the reader in constructing their first Mind Map. You can’t get any more guidance than that. The difference form other self help books (from my limited exposure to self help books) is that the author is very clear on one thing – you need to practice to get it right and I quite agree with that. There is one thing I would crib about – I didn’t fully grasp the point of making a separate section on Communication, sure the facts are interesting but it doesn’t add anything to the technique of Mind Mapping.

The verdict: The book quite serves its purpose. If you are planning to learn Mind Mapping, this book is quite a good resource with all its exercises and detailed guidance.

CoI – I received this book free of cost as part of BlogAdda book review program.

This review is a part of the Book Reviews Program at BlogAdda.com. Participate now to get free books!

On the death of Infants

Posted: Saturday, December 3, 2011 | Posted by Debajyoti Datta | Labels: , 0 comments


The recent controversy and allegations over the infant death in the BC Roy Post-Graduate Institute of Paediatric Sciences demands that we examine the issue critically. Every death is lamentable but we should also recognize that every death is not preventable unless action is taken in a timely manner. Only by examining what went wrong we can begin to rectify them.

Image Courtesy : Rana2030

Various reports from the media state that initially 12 infants died within a period of 48 hours and later 3 more deaths occurred in the third day taking the toll to 17 infants in 3 days (1, 2).

The role of the media here calls for criticism. What the media is trying to report is the rate of infant death but it is meaningless unless we know how many infants were admitted in the hospital in these days. The media failed to mention the prevailing infant mortality rate in the hospital. Was the death rate in these 3 days significantly higher than the prevailing death rate? Without this crucial information any reporting of the incident only helps in polarizing and sensationalizing the issue and is of no real help.

Let us look at some data. I couldn’t find data specifically for the hospital in question but data was available for another hospital in the city (3). Although it is not ideal, we can use it as a proxy for the absent data from the hospital in question. A total of 1216 infants were admitted to a tertiary care hospital in a year. 286 died, making the infant mortality rate 23.52%/year which is pretty high. Consider this, if 20 infants were admitted everyday for 3 days, we can expect that a total of 14 would have died. This example of course has several limitations. For starters we don’t know how many infants were actually admitted to the hospital in question. We don’t know the prevailing infant mortality in the hospital. It may so happen babies who were very sick and couldn’t be managed elsewhere were referred to the BC Roy hospital as it is a specialized hospital. What I want to say with this example is that we can’t draw any meaningful conclusion from what the media reported though it is a sensitive issue on which we should have an informed opinion.

The knee-jerk response of the government is also unfortunate. The solution that the government proposes is opening of more Sick Newborn Care Units all across the state. This is commendable but we should realize that this constitutes what the public health doctors term as secondary prevention, meaning taking early action after the disease/event has already occurred. A better way is primary prevention which aims at preventing the disease/event from happening at the first place. Primary prevention demands long term commitment from the all the parties involved. Let us look at the common causes of hospitalized infant deaths in the city – septicemia, birth asphyxia, prematurity, acute respiratory tract infections, meningitis, congenital anomalies, congenital heart defects etc (3).

If we examine the risk factors for the causes of infant death, we can see that many of them are preventable. For example higher paternal education significantly decreases the risk of birth asphyxia. Low birth weight is an established risk factor for birth asphyxia and chronic mater malnutrition is one of the major causes of low birth and prematurity. Poor prenatal care, low socioeconomic status, low birth weight and birth asphyxia itself are causes of septicemia in infants (4, 5, 6).

There are few factors which if controlled will lead to a decreased incidence of the diseases affecting neonates and by extension a reduction in the infant deaths. Maternal nutrition, proper antenatal checkups, improvement in the socioeconomic and living standards of the mothers, proper education of the parents are some of the areas where improvement will lead to a better outcome. This, in conjunction with improved secondary prevention strategies will hopefully prevent further occurrences of such incidences in future.

Conflict of interest – I had attended few lectures of Dr. DK Paul, Superintendent of BC Roy Post-Graduate Institute of Paediatric Sciences when he was posted at my college.

References:

  1. MARCUS DAM. Four more crib deaths in Kolkata hospital, 12 in Bardhaman hospital. The Hindu. October 29, 2011
  2. Infant deaths in B C Roy hospital again. The Telegraph. 26th October, 2011.
  3. Roy, RabindraNath. (2008) Mortality pattern of hospitalized children in a tertiary care hospital of Kolkata. Indian Journal of Community Medicine, 33(3), 187
  4. Lee, A. CC. (2008-05-01) Risk Factors for Neonatal Mortality Due to Birth Asphyxia in Southern Nepal: A Prospective, Community-Based Cohort Study. PEDIATRICS, 121(5), e1381-e1390.
  5. Anderson-Berry AL. Neonatal Sepsis. Medscape Reference.
  6. Paul VK, Singh M, Sundaram KR, & Deorari AK. (1997) Correlates of mortality among hospital-born neonates with birth asphyxia. The National medical journal of India, 10(2), 54-7.

An exercise on detecting fallacies in newspapers

Posted: Wednesday, November 16, 2011 | Posted by Debajyoti Datta | Labels: , 0 comments



I am quite fond of Justice M. Katju, the newly appointed chairman of the Press Council of India. For starters, he has correctly identified the deep seated rot within the Indian media. Will he able to do something about it? Only time will tell and I certainly hope he does but already the apologists for the New Media are coming out the woodwork and twisting his words to portray him a negative light. Some of these articles criticizing Justice Katju are out right non-sense and don’t deserve any attention of our grey cells but others are putting the spin with much more subtlety. Case in point being this piece published in the Hindu by Nirupama Subramanian. Unless you read the article critically you might end up agreeing to the points of the author. So let me deconstruct the article and point out the fallacies.

While deconstructing I would make references to SCHOPENHAUER'S 38 STRATAGEMS or 38 ways to win an argument, please note that it is something of a satire and really tells you how not to argue. So I begin my first salvo –

Nirupama Subramanian wrote: 
“Yet I find myself disagreeing with Justice Katju's broad swipe. It is easy to tar the entire media with one broad brush of criticism. But not all journalists are the same, just as not all judges are the same. There are many journalists who are doing exactly what Justice Katju thinks journalists should be doing, and they are not necessarily all high-profile.”

I refer to Schopenhauer’s first and sixth points - 
Carry your opponent's proposition beyond its natural limits; exaggerate it. The more general your opponent's statement becomes, the more objections you can find against it. The more restricted and narrow his or her propositions remain, the easier they are to defend by him or her.
And
Another plan is to confuse the issue by changing your opponent's words or what he or she seeks to prove.

Why do I say so? Nirupama Subramanian grossly exaggerates and misrepresents what justice Katju is saying. This is what Justice Katju actually said
"I am not saying that there are no good journalists at all in the media. There are many excellent journalists. P. Sainath is one of them, whose name should be written in letters of gold in the history of Indian journalism."

So Niruspama Subramanian constructs a straw man of her own and then proceeds to argue against the straw man. Unless we recognize she is arguing against a straw man we might think she is right but in reality she is hopelessly wrong as Justice Katju never said what she would like us to believe he said.

Secondly, Nirupama Subramanian wrote: 
“It also needs to be said that the media have made a lot more positive contribution than they are given credit for. Much of the corruption that has come to light over the last one year, all the scams that are currently churning the Indian polity, would have gone unnoticed had it not been for exposés by news organisations.”

This is a very common divisionary tactic used to deflect criticism called “whataboutery”. There are two forms of whataboutery, the author uses the second from which goes like this – it is an attempt to downplay the seriousness of the behavior being criticized by pointing to topics the commenter considers to be more important. 

To give a more straight forward example - consider a man who beats up his wife regularly. When produced in court, the accused gives the excuse, "My Lord, but I always obeyed the law before, I paid my taxes, I help my neighbors". Now should the man not be punished for beating up his wife based on this excuse? Compare with what the author is saying that the media is involved in paid news etc but in media's defense they have also uncovered scams so they shouldn't be criticized for paid news! The argument put forward is ridiculous. Justice Katju has never denied the good work done by the media; instead he is criticizing those aspects of the media which he considers unethical. By putting forward the argument of whataboutery, Nirupama Subramanian already concedes that Justice Katju is correct, so she tries to direct our attention to what she considers the good aspects of the media.

Lastly, Nirupama Subramanian wrote: 
“But it is also expected of the chairman of the Press Council to separate himself from Everyman, and take a more nuanced view of the complex terrain before him.”

In this she reveals her true intentions. Why must Justice Katju distance himself from the ordinary individual? Why are journalists so afraid of ordinary individuals? Is it because they realize that we mere mortals can see through their nonsense? What complex terrain is there? What is so complex in understanding that paid news is unethical and should be punishable? What does she mean by nuanced view? This is the prime example of the mentality of the some journalists, who fashion themselves as intellectuals. They seem to consider to us as retarded who will eat whatever they feed us.

Outbreak of viral encephalitis in Bihar, India

Posted: Monday, November 14, 2011 | Posted by Debajyoti Datta | Labels: , 0 comments

An outbreak of viral encephalitis is ravaging the childrenof Magadh division in Bihar India. This is the second wave of encephalitis that has hit the state after the rainy season with 383 children affected and 82 lives lost. The local health authorities are ill equipped to handle such an epidemic and Bihar being one of the poorest states of India does not help much. Conveniently the local media has given it scant or no coverage.

Image courtesy: The Hindu
 Suspected causative agents

It appears that more than one microorganism is responsible for the outbreak with the Japanese encephalitis virus (JEV) being the prime suspect. It is estimated that at least one third of the cases are caused by JEV which is endemic in the region. JEV, a flavivirus, consists of eight virus species and two subtype viruses. Japanese encephalitis is a zoonotic disease with the zoonotic cycle affecting mosquitoes and pigs and/or water birds. Humans are dead end hosts and become infected accidentally. The major vector implicated in transmission to humans is the mosquito Culex tritaeniorhynchus, breeding mainly in rice paddies. Both rice paddies and pigs are abundant in rural Bihar, perpetuating the epidemic.

JEV has an incubation period of 5 to 15 days with the average incubation period being 6-8 days. There is usually a prodromal period at the onset characterized by nausea, vomiting, diarrhea, fever and headache. The prodromal period, which can last for several days, is followed by higher mental functional abnormalities ranging from mild confusion to coma. Seizures are common in children. Tremors and other movement disorders may occur. Acute flaccid paralysis resembling poliomyelitis may also occur. The fever generally disappears by the second week of the disease followed by the onset of extrapyramidal symptoms like chorea.

On examination, hypertonia and hyperreflexia may be present. There may be cranial nerve involvement like facial palsy etc. Parkinson like extrapyramidal features may be present. Mortality in resource poor settings is about 35%.

In ProMED-mail, an internet based outbreak reporting system of the International Society for Infectious Diseases, enterovirus infection has also been suggested as a plausible etiologic agent. However there is no evidence available at present for an enteroviral cause.

Failure of Policy?

Following an outbreak of JE in 2009 in the Bodh Gaya division of Bihar, a massive vaccination campaign was launched in that division and no further cases of JE were reported. Inexplicably such vaccination campaigns were not organized in other divisions of the state. Result – fresh outbreak in another division (Magadh).

The local hospital is also in shambles with water and power shortages and the only ventilator lying useless.

ResearchBlogging.org Mackenzie, J., Gubler, D., & Petersen, L. (2004). Emerging flaviviruses: the spread and resurgence of Japanese encephalitis, West Nile and dengue viruses Nature Medicine, 10 (12s) DOI: 10.1038/nm1144

Actionable evidence: How to tackle obesity in primary care?

Posted: Tuesday, October 25, 2011 | Posted by Debajyoti Datta | Labels: , 7 comments

Scenario: A 45 year old male with a BMI of 32 presents to his primary care physician. What intervention should be suggested to him to reduce his BMI? Should only behavioral modification be adequate or should orlistat be added to it?

Evidence: A recent study titled “Effectiveness of Primary Care–Relevant Treatments forObesity in Adults: A Systematic Evidence Review for the U.S. PreventiveServices Task Force" published in the Annals of Internal Medicine looks into the evidence.

The study tried to answer 4 key questions –
  1. Is there direct evidence that primary care screening programs for adult obesity or overweight improve health outcomes or result in short-term (12 to 18 mo) or sustained (>18 mo) weight loss or improved physiologic measures? a) How well is weight loss maintained after an intervention is completed?
  2. Do primary care–relevant interventions (behaviorally based interventions and/or pharmacotherapy) in obese or overweight adults lead to improved health outcomes? a) What are common elements of efficacious interventions? b) Are there differences in efficacy between patient subgroups (i.e., age 65 y or older, sex, race/ethnicity, degree of obesity, baseline cardiovascular risk)?
  3. Do primary care–relevant interventions in obese or overweight adults lead to short-term or sustained weight loss, with or without improved physiologic measures? a) How well is weight loss maintained after an intervention is completed? b) What are common elements of efficacious interventions? c) Are there differences in efficacy between patient subgroups (i.e., age 65 y or older, sex, race/ethnicity, degree of obesity, baseline cardiovascular risk)?
  4. Do primary care–relevant interventions in obese or overweight adults lead to short-term or sustained weight loss, with or without improved physiologic measures? a) How well is weight loss maintained after an intervention is completed? b) What are common elements of efficacious interventions? c) Are there differences in efficacy between patient subgroups (i.e., age 65 y or older, sex, race/ethnicity, degree of obesity, baseline cardiovascular risk)?

Outcome: The first key question remains unanswered as the authors were unable to identify any study comparing screening vs non-screening of obese individuals.

The second, third and fourth key questions were answered. The summary –

Behavioral interventions

Parameter
Outcome
Weight Loss
Weighted mean difference in mean weight change between behavioral intervention and control group is -3.01 kg 95% CI (-4.02 to -2.01) at 12 to 18 months. Behavioral interventions lasting longer continued to show weight loss. Weight los was maintained up to a year following active intervention phase.
Mortality
No difference in death rate but limited by small number of trials.
Cardiovascular disease
No difference in CVD events or CVD related deaths in 3 large good quality trials
Hospitalization
No difference, limited by low hospitalization rate.
Health related quality of life/depression
No difference in depression, small favorable change of health related quality of life with weight loss
Incidence of diabetes mellitus
Weight loss of 4 to 7 kg reduced diabetes incidence by 50% or more over 2 to 3 years.
Glucose tolerance
Mean decrease in glucose level = 0.30 mmol/L (5.4 mg/dL)
Lipids
Weighted mean difference in LDL cholesterol level between treatment and control group = -4.94 mg/dL 95%CI (-7.32 to -2.56)
Blood pressure
Weighted mean difference in mean change in blood pressure between treatment and control group = -2.48 mmHg 95%CI (-3.25 to -1.71)
Waist circumference
-2.7 cm 95%CI( -4.1 to 1.4)
Adverse effects
None

Orlistat (Note- Almost all the trials of orlistat had simultaneous behavioral interventions)

Parameter
Outcome
Weight Loss
Weighted mean difference between behavioral intervention and control group is -2.98 kg 95% CI (-3.92 to -2.05).
Mortality
There were 4 studies which reported this outcome. Each study reported 1 death in in the orlistat group, but no clear relationship with treatment.
Cardiovascular disease
Not reported.
Hospitalization
Not reported.
Health related quality of life/depression
No difference in depression, Orlistat had greater satisfaction with treatment, less overweight distress and improvement in the vitality subscale of SF – 36.
Incidence of diabetes mellitus
Decreased incidence by 9-10% but concerns regarding generalizability and reliability.
Glucose tolerance
Mean decrease in glucose level = 0.31 mmol/L (5.5 mg/dL). Glucose reductions are greater in orlistat than placebo possibly because they were conducted in diabetic patients.
Lipids
Weighted mean difference in LDL cholesterol level between treatment and control group = -11.37 mg/dL 95%CI (-15.75 to -7.00)
Blood pressure
Weighted mean difference in mean change in blood pressure between treatment and control group = -2.04 mmHg 95%CI (-2.97 to -1.11)
Waist circumference
-2.3 cm 95%CI( -3.6 to -0.9)
Adverse effects
Gastrointestinal symptoms of mild to moderate intensity which resolves spontaneously, liver injury, vitamin E and K deficiency, increased incidence of hypoglycemia.

The authors also examined metformin which had modest effects on weight loss -2.85 kg 95%CI (-3.52 to -2.18).

Comment
The behavioral interventions included counseling regarding the importance of diet and exercise. There the interventions were not described fuly in the study. There was variability in the methods employed for behavioral modifications in the between the studies. On the other hand, orlistat studies had high attrition rate and were mostly funded by pharmaceutical companies.

Bottom line
In the primary care setting, behavioral intervention is effective and safe and should be considered as a first line therapy for weight loss. Orlistat may be added later. There are significant adverse effects associated with orlistat. Metformin may be tried in diabetics.

ResearchBlogging.org Leblanc ES, O'Connor E, Whitlock EP, Patnode CD, & Kapka T (2011). Effectiveness of primary care-relevant treatments for obesity in adults: a systematic evidence review for the u.s. Preventive services task force. Annals of internal medicine, 155 (7), 434-47 PMID: 21969342

Actionable evidence: Injectable contraceptives increase the risk of HIV infection

Posted: Thursday, October 20, 2011 | Posted by Debajyoti Datta | Labels: , 3 comments


I was thinking of a new category of posts which I would be calling actionable evidence. Actionable evidence is that evidence which you can immediately put into practice; these are of direct clinical relevance. So to start this off I have selected a very important study that came out in the Lancet Infectious Diseases titled “Use of hormonal contraceptives and risk of HIV-1 transmission: a prospective cohort study”. Here is the main outcome of the study –

Risk of HIV acquisition in women


Hazard ratio (95% CI) Adjusted Cox proportional hazards regression analysis
Hazard ratio (95% CI) Adjusted marginal structural models analysis
Any Hormonal Contraception
1.98 (1.06-3.68)*
1.84 (0.98-3.47)
Injectable
2.05 (1.04-4.04)*
2.19 (1.01-4.74)*
Oral
1.80 (0.55-5.82)
1.63 (0.47-5.66)

*significant


Risk of transmission from women to men


Hazard ratio (95% CI) Adjusted Cox proportional hazards regression analysis
Hazard ratio (95% CI) Adjusted marginal structural models analysis
Any Hormonal Contraception
1.97 (1.12-3.45)*
2.05 (1.12-3.74)*
Injectable
1.95 (1.06-3.58)*
3.01 (1.47-6.16)*
Oral
2.09 (0.75-5.84)
2.35 (0.79-6.95)

*significant


Recommendation of the authors - Women should be counseled about potentially increased risk of HIV-1 acquisition and transmission with hormonal contraception, especially injectable methods, and about the importance of dual protection with condoms to decrease HIV-1 risk.

Comment –
Injectable contraceptives are used as suitable contraceptive method by many women. It has the advantage of ease of use. For example, DMPA (depot medroxyprogestrone acetate), one of the injectable contraceptives, can be taken at 3 monthly intervals. You don’t have to worry about contraceptives during these 3 months which is a problem with the oral pill, which has to be taken daily and one might forget to take it.

The study was of prospective cohort design with African serodiscordant (one partner with HIV infection and other partner free from infection) couples, though the majority of the data is taken secondarily from a randomized control trial. Basically the authors recruited HIV serodiscordant couples and subsequently they tested the HIV uninfected partner to see if they are getting infected. After doing this, they compared if the rate of infection  was more in seronegative subjects who were using hormonal contraceptives or in case of male subjects whose female partners were using hormonal contraceptives with those who were not using hormonal contraceptives. They followed the subjects for 24 months with mean follow up in seronegative women being 18 months and mean follow up of 18.7 months for seronegative men.

Overall this is a well conducted study, though there are few issues related to the methods. Firstly, the contraceptive use was self reported. Secondly, the use of injectable hormonal contraception was quite low among the participants but the study was adequately powered. Thirdly, the incidence of HIV infection was quite low. Fourthly, it is not clear to me whether the assessors were blinded to the nature of contraception use by the participants.

Before you ask the obvious, the authors controlled for the number of unprotected sexual intercourse. Even after controlling for unprotected sexual intercourse, injectable hormonal contraceptives significantly increased the risk of HIV infection. This suggests that something other than just unsafe sex is at play here.

Bottom line – Injectable hormonal contraceptives might increase the risk of HIV infection, evidence from observational study. All women using injectable hormonal contraceptives should be counseled to use condoms during intercourse to prevent HIV infection. Randomized controlled trial needed to see if the association holds.

ResearchBlogging.org Heffron R, Donnell D, Rees H, Celum C, Mugo N, Were E, de Bruyn G, Nakku-Joloba E, Ngure K, Kiarie J, Coombs RW, Baeten JM, & for the Partners in Prevention HSV/HIV Transmission Study Team (2011). Use of hormonal contraceptives and risk of HIV-1 transmission: a prospective cohort study. The Lancet infectious diseases PMID: 21975269