Apixaban in ESRD and Atrial Fibrillation

Patients with ESRD (end-stage renal disease) are usually prescribed coumadin when they need anticoagulation; the reason being that we know very little (or not at all) about the effect of new oral anticoagulants in patients with ESRD.

In this study, Siontis et al performed a retrospective cohort study of Medicare beneficiaries with ESRD and atrial fibrillation, the later an indication for anticoagulation. Outcomes were compared between patients who were treated with apixaban versus patients who were treated with warfarin. Authors examined the survival difference between the two groups for stroke or systemic embolism, major bleeding, gastrointestinal bleeding, intracranial bleeding, and death using Kaplan–Meier analyses and hazard ratios (HRs) and 95% CIs were obtained using Cox regression analyses.

Authors found that there was no difference in stroke and systemic embolism between the two groups. However, the group taking apixaban had 28% lower risk of major bleed.

While this is retrospective data, and clinical trial data is lacking, this study will support the use of new oral anticoagulants in ESRD patients.

Is Science Getting Less Bang for its Buck?

Here is an interesting article published in The Atlantic which claims that the productivity in science is declining. The investment in science is increasing but the pace of novel or truly important discoveries is decreasing. They give various reasons; I have few additional thoughts that I assume authors thought of but were not included in this piece.

1. The age of scientist at discovery is increasing due to the large volume of knowledge we ‘force’ young scientist to learn. We have formalized ‘learning’ to an extent that we feel it is obligatory for anyone to ‘know’ it all before moving forward. Just as an example, the ‘required’ courses to take are often not directly relevant to the learner’s interest or the to the topic. WE have added those without any scientific evidence that such additional courses help with discovery. We preach evidence, we prefer not to teach by science. And when we try to accumulate evidence, we do it using irrelevant outcomes. This is the problem with education in general and not with science education.

2. Truly novel discoveries happen in spurts. Discovery of zero was truly important, one may argue more important than general relativity. Perhaps discovery of algebra and calculus were also more important, and fundamental, than general relativity. But these discoveries are not ‘novel’ anymore for us. I believe new discoveries happen after we have utilized the older discoveries to close to the fullest extent. Imagine a new discovery as a new house; once we build a new house, we start filling it, decorating it, accumulating useful (and some junk) ‘stuff’. This is perhaps what happens with truly important discoveries. A truly important discovery is followed by many small discoveries over next many years until the potential of new discovery has been fully realized and then another new discovery happens.

Serum creatinine in critically ill patient

An interesting, short and sweet article in JAMA highlighting that serum creatinine increase in critically-ill patients may underestimate the degree of AKI.

They give following reasons for this underestimation:
1. Creatinine production decreases in sepsis, hence there is decreased release of creatinine and slow rise in serum creatinine
2. Critically-ill patients receive large-volume resuscitation and hence dilute serum creatinine. Of note, the volume of distribution of creatinine is about 65% of body weight.

Having said that, there does not appear to be any good alternatives for determining renal function ad GFR estimation in such population.

Vitamin D and Cardiorespiratory Fitness

Here is a study just published showing relationship between cardiorespiratory fitness and vitamin D levels. The study adjusted for various confounders and the relationship was independent of these confounders. The study is cross-sectional and hence the direction of causal effect is difficult to determine. That is, whether greater cardiorespiratory fitness is associated with more time spent outside and hence more sunlight exposure and vitamin D formation or whether vitamin D, through its effects on muscles, nerves, bones, results in higher cardiorespiratory fitness

Deep Learning in Pathology

Here is an intersting article, showing the role of AI in pathological diagnoses. Medical speciliaties most dependent on pattern recognition, such a pathology, dermatology, or radiology, are more likely to get AI assistance sooner. With time, it is quite possible that AI can replace such physicians. For now, it appears that AI will help them work faster. Remember, increasing efficiency means need for fewer physicians in such specilaties and possibly decliing salary.

Incentives and Work

An interesting article which is also very germane to academic physicians. In particular the sentence “what drives most academics to the university on a given day (including evenings and weekends) is not the money (otherwise we would work in the private sector) or the stability of the income stream (because the probability of losing a job is close to zero for a tenured academic). In fact, Stern (2004) shows that “scientists pay to be scientists.”  is right on the spot. One can say about physicians in academia that they “pay to be in academics”. In almost every case, they can earn quite a bit more in private practice. It is the meaning in their work that motivates them.

Aspirin and Body Weight

Low dose aspirin has been shown to reduce cardiovascular events but the observed effect may vary by weight. In fact, in one of our studies, we have shown that not only obese individuals had greater baseline platelet reactivity, they also had greater residual platelet reactivity after low-dose aspirin therapy. Comparing obese and nonobese individuals after aspirin therapy, results for aggregometry to collagen were 6.7 vs 6.1 ohms, P=.008; aggregometry to adenosine diphosphate were 13.1 vs 11.8 ohms,P<.0001; aggregometry to arachidonic acid (AA) were 4.9% vs 8.3% nonzero aggregation, P=.002; urinary excretion of 11-dehydro-thromboxane B2 (Tx-M) were 4.9% vs 8.3% nonzero aggregation, P=.002; and aspirin resistance were 26.% vs 20.5%, P=.002; respectively.

Now an individual-patient meta-analysis of primary prevention randomized controlled trials with low-dose aspirin have shown that clinical outcomes are also different in patients with weight>70Kg than in patients with weight<70Kg. On the other hand, when a higher dose of aspirin was examined, individuals with weight>70Kg obtained clinical benefits. Clinical benefits were not limited to cardiovascular outcomes but also included colorectal outcomes.

An obvious implication of such studies is that individuals with weight>70Kg should take perhaps more than one baby aspirin to receive benefit from aspirin.

Artificial Intelligence & Medicine

Some recent articles ……

Goldberg JE, Rosenkrantz AB. Artificial Intelligence and Radiology: A Social Media Perspective. Current Problems in Diagnostic Radiology. 2018 Jul 23.
An interesting study examining the types of conversations on Twitter about the role of artificial intelligence in radiology. It appears that most tweets (or linked websites) were upbeat and wanted radiologists to continue supervision of AI-run diagnostics.

Meskó B, Hetényi G, Győrffy Z. Will artificial intelligence solve the human resource crisis in healthcare?. BMC health services research. 2018 Dec;18(1):545.
This article expresses the hope that artificial intelligence may be able to help in mitigating human resource crisis in health sector.

dos Santos DP, Giese D, Brodehl S, Chon SH, Staab W, Kleinert R, Maintz D, Baeßler B. Medical students' attitude towards artificial intelligence: a multicentre survey. European radiology. 2018 Jul 6:1-7.
This article examines the attitudes of undergraduate medical students towards artificial intelligence in radiology and medicine. Students think that artificial intelligence will revolutionize the practice of medicine, in particular radiological diagnosis.

Struggling Healthcare Organizations

A systematic review identified five characteristics of healthcare organizations that are struggling to improve quality.

1.  Poor organizational culture: Such as limited ownership, not collaborative, hierarchical, with disconnected leadership

2. Inadequate infrastructure: Limited quality improvement, staffing, information technology or resources

3. Lack of a cohesive mission: Mission conflicts with other missions, is externally motivated, poorly defined or promotes mediocrity

4. System shocks: Events such as leadership turnover, new electronic health record system or organizational scandals that detract from daily operations

5. Dysfunctional external relations with other hospitals, stakeholders, or governing bodies.

Physician Competition Effects

An interesting study examined the impact of competition among cardiologists on service provision and patients' health outcomes in the United States. Authors found that cardiologists in more concentrated markets perform more diagnostic procedures. On the other hand, higher concentration result in fewer readmissions but has no effect on mortality.

Medical Bill Collections Decrease with Patient’s Age

An interesting study that finds that the average size of medical debt decreased nearly 40 percent from when patient was twenty-seven old to when sixty-four years old. Authors thought that this was with an increase in health insurance coverage and incomes.

Well-being–some readings

Well-being has been a focus of philosophers for centuries. While philosophers tend to question how we should live, the very answer to this question begs the question how living that way will make us better, that is, how living in a certain way will make us live well.

A little self-reflection will help you to realize that there are many things that make you live well, make you happy, excited, or content, or conversely make you feel sad. Think of the things that make you feel happy. Often these things include relationships, friends, money, accomplishments. Now think of things that make you feel sad; these may include anxiety, worry, illness, poverty. Lists of both things, things that make us happy and things that make us sad, can be long and likely will vary from person to person (at least to some extent). The question one may ask is what is it that one thing (or a small group of things) that is fundamentally deterministic of feeling well.

Hedonism is a theory of well-being which focuses on individual’s pleasure or pain. Thus, pleasure is associated with high well-being and pain is associated with poor well-being. On the other hand, perfectionism focuses on our ability to develop certain virtues or characteristics. Perfectionism is similar to eudaimonia; well-being is associated with developing virtues that are human nature. Desire theory proposes that well-being is present when one gets what one desires; in other words, fulfillment of desires is associated with well-being. Objective list theories are a set of theories that have in common a list of things that make one happy; list from one theory may not overlap with another theory. This group of theory highlight the fact that it is not easy to define what constitute well-being.

Machine Learning Predicts Clinical Deterioration

Edelson and her colleagues trained a gradient boosted machine model on a dataset of almost 300K patients and were able to predict clinical deterioration better than the modified early warning (MEWS) system. Here is the link for the abstract that was presented at ATS 2018.

The simplicity of the tool which uses only age, heart rate, and respiratory is really impressive. Interestingly, respiratory rate is often the least accurately measured vital sign in the hospitals despite its simplicity. A more accurate measurement of respiratory rate can potentially help better predictive models to predict clinical worsening in a patient’s condition. Better prediction can not only help to patients by focusing on the cause of clinical worsening but will also help to more optimally utilize resources within the hospital.

Some Interesting Recent Articles from bioRxiv

1. The Subtype Specificity of Genetic Loci Associated with Stroke in 16,664 cases and 32,792 controls: Using Bayesian multinomial regression in 16,664 stroke cases and 32,792 controls of European ancestry, investigators wanted to determine the most likely combination of stroke subtypes affected for loci with published genome-wide stroke associations. Of the 16 loci, seven influenced both ischemic and hemorrhagic stroke, an EDNRA locus demonstrated opposing effects on ischemic and hemorrhagic stroke. No loci were predicted to influence all stroke subtypes in the same direction.

2. Sensitivity to Affective Touch Depends on Adult Attachment Style: Higher scores on an attachment anxiety dimension (but not an attachment avoidance) were associated with reduced pleasantness discrimination between affective vs. non-affective, neutral touch.

3. The GRE Over the Entire Range of Scores Lacks Predictive Ability for PhD Outcomes in the Biomedical Sciences: GRE scores are often assumed to be predictive of student success in graduate school; however, authors found no association in admission data.

MIMIC Database

I ran across this publicly available dataset which looks great for someone interested in data-analysis. The dataset appears to be extensive. I have not worked with its analysis yet but this will be something that will be on my ‘things-to-do” list. According to its website “MIMIC is an openly available dataset developed by the MIT Lab for Computational Physiology, comprising deidentified health data associated with ~40,000 critical care patients. It includes demographics, vital signs, laboratory tests, medications, and more.”

Proposed Changes to Medicare Physician Fee Schedule 2018

Last week, the Centers for Medicare & Medicaid Services (CMS) proposed a rule to update payment policies, payment rates, and quality provisions for services furnished under the Medicare Physician Fee Schedule (PFS) on or after January 1, 2019. Some of the proposed changes include:

1. Streamlining E&M payment with reduction in clinical documentation burden

2 .Recognition of services based on the use of communication technology

3. Creation of a bundled episode of care for substance abuse disorders

4. Flexibility on the use of radiology assistants

5. Removing functional status reporting requirement for outpatient treatment

6. A slight increase of $0.06 per RVU

7. Updating the direct practice expenses based on recent survey

8. Medicare telehealth services

9. Request for information on price transparency

10. Changes to the Quality Payment Program

Here is the link for those interested in learning more about these proposed changes

Physician White Coats and Patient Preference

An interesting study published in the BMJ Open and an interesting overview here by Brad Flansbaum.

Bottom line, formal physician attire with a white coat was rated significantly higher by patients than any other attire. Just an re-emphasis on the fact that ‘packing’ matters. One may want to to look at this that those physicians who take their profession seriously also try to wear a better representative attire than others; I am sure there a large number of physicians who may strongly disagree with this assessment.

Vitamin D Levels in African Americans

Vitamin D is associated with bone and calcium metabolism. However, more recently, studies have increasingly reported the effect of vitamin D on other organs and systems. For example, vitamin D is associated with all-cause mortality and cardiovascular mortality. Vitamin D is also associated with peripheral arterial diseases. Further, vitamin D has been associated with serum C-reactive protein levels (a biomarker of systemic inflammation). Vitamin D has also been associated with liver function.

African Americans tend to have significantly lower levels of serum vitamin D and hence may be at a higher risk of low vitamin D related morbidity. The reason perhaps lies in genetics, at least that is what this study suggests. Investigators assessed the association between percentage of European ancestry and serum vitamin D level among 2,183 African-American women. An algorithm implemented through a software was used to estimate the percentage of European ancestry versus African ancestry in each individual. After adjustment for various potential confounders (genotype batch, age, body mass index, supplemental vitamin D use, ultraviolet B radiation flux in the participant’s state of residence, and season of blood draw), investigators reported that each 10% increase in European ancestry was associated with a 0.67-ng/mL increase in serum vitamin D concentration (95% confidence interval: 0.17, 1.17).

Question remains if the low serum levels of vitamin D are clinically meaningful in African Americans. Do low serum vitamin D levels are reflective of low tissue levels (or effective tissue levels)? These type of questions will need a different and more involved study designs for answers.

Diabetes and Risk of Cancer

Patients with diabetes mellitus are at increased risk of cardiovascular complications such as heart attack, stroke, peripheral arterial disease etc. Commonly, the cause of death in diabetes is due to cardiovascular events.

Does diabetes increases risk of cancer in addition of increased risk of cardiovascular diseases? This important question was explored in this interesting study of over half-million Chinese. Investigators enrolled patients with and without diabetes and without any prior diagnosis in the study between 2004-2008 and then followed them until the end of 2013 for development of any cancer. During the follow-up period, they found more than 17,000 cases of cancer. Diabetes was associated with an increased risk of all-cause cancer and site-specific cancer.

Diabetes increased the risk of overall cancer by 13%, of liver cancer by 51%, of the pancreatic cancer by 76% and of the breast cancer by 21%. Investigators further reported that higher random blood glucose levels were associated with increased risk of cancer. Perhaps, it is the elevated blood glucose levels in diabetics that is responsible for cancer.

Medical Procedures and Heart Valve Infection

There are not free lunches! It is not uncommon to think that getting a procedure is better than not getting one, however, all procedures are associated with risks. For each procedure, the risk and benefits need to be carefully assessed before making a decision to undergo a procedure or not. Often having a procedure has greater benefits than risks, or so we assume.

While the benefits of a procedure are often clear, for example detection of coronary diseases when deciding about cardiac catheterization, the risks are not as well-studied. The list of risks associated with a procedure almost always includes risk of death and injury to some organ(s) but the actual incidence of these adverse events is usually poorly known, especially for for adverse events that are not immediately followed by the procedure (that is, there is lag-time between a procedure and associated adverse events). The more time lapses between the procedure and an adverse event, the difficult it is to ascribe adverse event to the procedure; generally so many other things, including additional procedures, happen in-between for diagnostic or therapeutic reasons.

One aspect of this issue is nicely addressed in an article published in the Journal of the American College of Cardiology where authors identified all adult patients treated for endocarditis in hospitals in Sweden and compared the occurrence of invasive medical procedures 12 weeks before endocarditis with a corresponding 12-week time period exactly 1 year earlier.

Of the 7,013 cases of infective endocarditis during the study period, several were strongly associated with cardiovascular procedures, especially coronary artery bypass grafting; procedures of the skin and management of wounds; transfusion; dialysis; bone marrow puncture; and some endoscopies, particularly bronchoscopy. A particularly interesting finding, that makes sense, is that the risk of infective endocarditis was higher if patient had a procedure while hospitalized than when patient had that procedure in outpatient setting. One way to look at this is to think that procedures should be done in outpatient setting but the converse is also possible (and more likely) that patients admitted to the hospital are sicker and hence are at higher risk of adverse effects.

Opioid use and voting Republican

A very provocative study by Goodwin et al have found that the chronic use of prescription opioid use was correlated with support for Republication candidate in 2016 Presidential elections. In case someone is concerned if the observed effect is due to the confounding by age (elderly people voting Republican but also having high need for opiates due to chronic diseases), authors did adjust for age and a broad category of other factors. I will invite everyone to read this study oneself.

Odds Ratio Limitations

Odds ratio is perhaps the most commonly reported effect size for binary outcome variables. The widespread use is likely due to the fact that logistics regression models provide odds ratio. Logistic regression models are relatively easy to implement and hence odds ratio is commonly reported. An article in JAMA recently highlighted some of the limitations of using odds ratio. The first two are well-known; the third one is not as well-known and its consequences are not fully realized. 

1) The interpretation is in odds and not in probabilities

2) Odds ratio approximates relative risk in limited situations only

3) Odds ratio depends on the the amount of unexplained variance; odds ratio may increase if the amount of unexplained variation decreases due to inclusion of strong explanatory variables in the model. Odds ratios obtained from same data set but different model may not be comparable due to the above limitation.

Productivity Paradox and EHR

Bob Wachter and Michael Howell are optimistic about the future improvements in health information technology and its impact on physicians. I share their enthusiasm and I am optimistic about an increase in productivity in healthcare sector. And why not? Its about time.

Productivity in every other sector has resulted in decreasing utilization of human resources and increasing production of goods. However, such is not the case in healthcare. A physicians still sees about the same number of patients in a day as he/she used to see 50 or 100 years ago. It is quite possible that the number patients seen might have dropped due to documentation and other requirements. The result is evident; healthcare sector now accounts for almost one-fifth of the GDP in the US. Much of this has to so with the lack of growth in productivity in healthcare sector as compared to other sectors.

What is promising is that artificial intelligence will likely to increase productivity in the healthcare. I don’t think that this will come through improvements in health information technology (HIT). I believe it will come with better utilization of HIT as data repository for learning algorithms. Technology will also help in data capture, and it does so in many ways even now, but most importantly in data inference. However, it will not be good for an average physician.

Remember, productivity can increase only if more patients can be seen by fewer physicians (or healthcare workers). That is not possible with one physician simultaneously seeing several patients. It is possible only when machines see most patients and physician sees patients only in those situations where algorithms have not gotten enough data to develop a routine.

And what those situations will occur in relatively rare conditions. These will not our usual common diseases, what we might call ‘bread-and-butter’ medicine. Rather these will be either rare diseases or rare manifestations of common diseases. A physician overseeing such a highly productive healthcare delivery system will have to be a master clinician and a superb diagnostician.

In other words, an increase in productivity in healthcare sector will spell the doom for majority of physicians ….. happy to hear what you think……….

Hospital Readmissions and Malnutrition

While it is easy to imagine how malnutrition can be related to excess readmissions, there are not very many studies examining this association. Of note, the CMS adjustment algorithm for expected readmissions takes into account malnutrition.

This retrospective study from Australia, examined this association among 26 253 admissions, representing 19 924 patients with a 6-month readmission rate of 44.8%. They found that malnourished patients had 40% higher risk of readmission within first week after discharge and 23% higher risk of readmission between the second week and 23rd week after discharge. Authors concluded that malnutrition was a strong predictor of unplanned readmissions and suggested examination of targeted nutritional interventions to lower readmission rate. 

Artificial Intelligence versus Human Doctors

While it is relatively easy to imagine artificial intelligence taking over pattern recognition type of physician work (such as reading images like radiologists or identify skin conditions by looking at the skin like dermatologists), the job of a general internist is much more demanding and requires assimilation of data inputs from a large number of sources, hence making it difficult for an artificial intelligence system to accurately predict a disease (or prepare a list of differential diagnoses).

On the other hand, the process is not, and should not be, very difficult for a well-crafted system. Razzaki et al tested such an artificial intelligence algorithm and compared it with physicians in its ability to predict diagnosis. For their study, they adopted a semi-naturalistic, role-play paradigm that simulated a realistic consultation between a patient and either their artificial intelligence system or a human doctor. Their study was designed to assess both the clinical (diagnostic and triage) accuracy and the ability to gather all of the relevant history from the patient. What they found was that their artificial intelligence algorithm was able to provide diagnostic and triage advice with a level of accuracy and safety approaching that of human doctors. If there study results are replicated then such systems may not only reduce costs and improve access to healthcare worldwide but may also provide better standardization of care delivered to patients.

Obesity and Increased Risk of Death

It is now well-known that obesity (BMI>29.9) or weight below the normal range (BMI<18.5) are associated with high risk of mortality. On the other hand, just being a little overweight (between 25 and 29.9) may reduce overall risk of death. These results were mainly based on a study published in 2005. However, there were some questions about possible bias due to incomplete adjustments for some risk factors such as smoking.

An update of these results with analysis for potential bias was recently published and available on NHANES website. Basically, the results remained the same and obesity and underweight both groups remained associated with high risk of death.

Of particular interest is the underweight group; while lay media has been focused on obesity, the other extreme, that is being underweight, is also associated with increased risk of death. In fact, the risk of death may be twice as high as normal weight in underweight individuals between the ages of 25 and 59 years.

Nutrition Data in NHANES

Ahluwalia et al published a review article (now updated) that gives a very interesting and comprehensive overview of dietary data collected in NHANES. The data is available publicly and dataset is really large allowing for examination of a large number of hypotheses.

Geographic Rounding and Patient Satisfaction

Geographic rounding is often touted as a way by which healthcare team can communicate better among themselves and thus patient will get similar messages from all team members. Further, team members will appear to patient have strong team-work . Lastly, this will also allow healthcare team to spend more time with patients. Hence, patient satisfaction will increase. While it sounds reasonable in theory, there is little evidence supporting this logical sequence. Siddiqui et al examined this question in their recent study published in the Journal of Patient Experience.

Interestingly, they found that the patients cared for by geographically localized teams did not have better patient experience. They suggest that other factors such as physician communication skills may overshadow the impact of having localized teams. Obviously, further research is needed to better understand organizational, team, and individual factors impacting patient experience.

Phytoestrogens and Liver

Genistein is a phytoestrogen with similarities to female sex hormones and, has been shown to prevent nonalcoholic fatty liver injury in animal studies but human studies are lacking.

In this study, authors, analyzed data from the National Health and Nutrition Examination Survey from 1999 to 2010 and examined the relationship between normalized urinary genistein (nUG) and serum ALT using linear regression models. Investigators further examined the differential effect of sex using an interaction term.

In almost 10K patients, authors found a statistically significant association between genistein and liver function in males, but not in females. At least for me, the sex-specific role of genistein in mitigating liver disease is very interesting.

Sepsis and qSOFA, SIRS, NEWS

Sepsis is a rather common admitting diagnosis to hospital with high mortality rate. Identifying patients who are at a higher risk of adverse outcomes may help to optimize resource allocation. To this end, initially SIRS definition was recommended. More recently, qSOFA is being promoted as a predictor of adverse events during hospitalization due to sepsis. However, there is a lesser known NEWS score that is also being used at few hospitals.
This study compared the three scores in a retrospective sample and found that NEWS may be similar or superior to qSOFA. Note that qSOFA (3 variables) is the quickest and simplest of the three while NEWS is the most complex (20 variables).

A Fantastic Weekly Update on Artificial Intelligence

I have been enjoying this weekly update by Azeem Azhar. And I invite you to try it too. Here is the link

http://www.exponentialview.co

SES Adjustment for Readmission Penalty

CMS started implementing the Hospital Readmissions Reduction Program (HRRP) on October 1, 2013, penalizing hospitals with higher readmission rates. While readmission rates were adjusted for several factors, socioeconomic status (SES) was missing leading to protests and lobbying by hospitals caring for poor people. Hence, in 2016 the US Congress directed the CMS to to adjust for low SES. In response, CMS has made following adjustments to HRRP.

1. Make five peer groups of hospitals based on SES. SES will be determined by the proportion of “dual eligible” Medicare beneficiaries (those who are also eligible for full Medicaid benefits).
2. Calculate the median excess readmission ratios (ERRs) within each peer group to adjust for penalties
3. Scale penalties using the budget neutrality factor.

Fuller and colleagues analyzed the effect of SES adjustments (as outlined above) and examined the effect on the number and distribution of penalized hospitals. An interesting read!

Protection of Gut Microbiome from Antibiotics

While antibiotics are essential for treatment of bacterial infection, an increasingly recognized adverse effect of antibiotic use is alteration in gut microbiome. The altered gut microbiome can result in several acute and long-term unhealthy effects. This small clinical trial tests the use of an adsorbent to to mitigate the effects of antibiotics on gut microbiome. Investigators found, using the shotgun quantitative metagenomics, that the richness and composition of the intestinal microbiota were largely preserved in subjects using antibiotics when co-treated with DAV132 (the adsorbent used in this study). This is an important study, and if the adsorbent is effective without compromising the antibiotic availability in blood, may be extremely useful in clinical medicine. 

Geographic Latitude, Blood Pressure, and Serum Cholesterol

This is a provocative study pointing out the association of geographic latitude with serum cholesterol levels. Obviously such studies, at country level, are fraught with biases including ecological fallacy. However, the underlying etiology of the observed differences need to be explored further.

Designing a RCT and Network Meta-analysis

A review of literature with possible meta-analysis of available data is often recommended before a randomized clinical trial (RCT) can be proposed. This article goes a step further and suggests using network meta-analysis for planning and designing a RCT. Authors emphasize that a trial design based on updating the evidence from a network meta-analysis of relevant previous trials may require a considerably smaller sample size to reach the same conclusion compared with a trial designed and analyzed in isolation.

Weak vs. Strong Social Ties

The relative contribution of the number of strong social ties versus the number of weak social ties to the health status was explored in this study. Authors examined social network characteristics as predictors of mortality in the Finnish Public Sector Study (n = 7,617) and the Health and Social Support Study (n = 20,816). At baseline, social network characteristics were surveyed. During a mean follow-up period of 16 years, participants with a small social network (≤10 members) were more likely to die than those with a large social network (≥21 members) (adjusted hazard ratio (HR) = 1.23, 95% confidence interval (CI): 1.04, 1.46). Mortality risk was increased among participants with both a small number of strong ties (≤2 members) and a small number of weak ties (≤5 members) (HR = 1.55, 95% CI: 1.26, 1.79) and among participants with both a large number of strong ties and a small number of weak ties (HR = 1.28, 95% CI: 1.08, 1.52), but not among those with a small number of strong ties and a large number of weak ties (HR = 1.04, 95% CI: 0.87, 1.25). Authors conclude that the number of weak ties may be an important component of social networks for mortality risk.

Diagnostics After Multilevel Regression in Stata

Here are few diagnostics that can be run in Stata after running a multilevel model

1. Assess normality of residuals

predict resid_std, rstandard
qnorm resid_std

2. Examine relationship between predicted and residual values

predict resid, res
predict fit, fit

3. Examine variance-covariance matrix

estat recovariance
estat recovariance, correlation

4. Determine Cook’s D and DFBETAs using MLT module

net install mlt.pkg    /* Installs MLT package*/
mltcooksd              /* reports Cook’s D of the whole model */
mltcooksd, fixed       /* reports Cook’s D of the Fixed part */
mltcooksd, random      /* reports Cook’s D of the Random part */
mltcooksd, approx      /* Uses approximation and returns results faster */

A very easy and simple video explaining Bayes Theorem

Must watch TED talk

Talks about how artificial intelligence algorithms are able to affect our opinions. We all are vulnerable, yes we ALL are.

Case against propensity scores

Here is an interesting video (couple of years old but still relevant)

CLABSI Trends and Parenteral Nutrition

Healthcare-associated infections (HAIs) harmful for patients and costly for the health system. Central line associated bloodstream infections (CLABSI) are the most costly of HAIs (between 45K to 55K per CLABSI), increase length of stay by several days, and increase mortality by 15% to 40%. Although the rate of CLABSI has been decreasing since the institution of several preventive practices, the rates remain pretty high.

Patients who receive parenteral nutrition have more than 4-times higher risk of CLABSI than those who who do not receive parenteral nutrition. However the data on the risk of CLABSI risk since the institution of penalties for CLABSI by CMS (Centers for Medicare & Medicaid Services) was not available, that was until the publication of study by Fonseca et al. They used data from all adult patient discharges between January 1, 2009, and December 31, 2014, from 2 affiliated hospitals in a large health system in New York City. They conducted univariate and multivariate analyses to examine the relationship and temporal trends between parenteral nutrition and CLABSIs.

Of the 38,674 patients with central lines, 3517 developed CLABSIs. Of these 3517 patients, 767 patients were prescribed parenteral nutrition. Patients who were prescribed parenteral nutrition were 2.65 times more likely to have CLABSI than patients without parenteral nutrition. What this study shows is that there has been a decrease in the risk of CLABSI among patients who receive parenteral nutrition, although the risk remains much higher. Obviously, this study advocates for additional research to identifies strategies to decrease the risk of CLABSI in patients who receive parenteral nutrition.

Burnout

Burnout among healthcare workers, particularly physicians, has gained increasing attention recently. The societal expectation is that physicians will be selfless and put their patient’s needs first. Often physicians are expected to work long hours and do whatever it takes to help their patient and to go the extra mile; in other words give one's all. Burnout is further exacerbated by the changes in national health system and healthcare organizations; such changes are resulting in work environments that are high in demands and low in resources.

However, what is burnout is open to interpretation. Experts still debate about the dimensions of burnout. The most common burnout measurement tool, Maslach Burnout Inventory (MBI) assumes three dimensions of burnout; emotional exhaustion (EE), depersonalization (DP), and personal accomplishment (PA). MBI has been criticized for its various aspects. For example, it measures three dimensions of burnout (EE, DP, PA) but recommends against merging those three dimensions to reach to the measurement of burnout itself. Thus, MBI is measuring three concepts but unable to define a single concept of burnout. Another criticism is that burnout is an amalgam of an individual state (EE), an undesirable coping strategy (DP), and result of the EE state (lack of PA). However, the biggest criticism of MBI is that it is not available in public domain.

The dimensions of burnout are open for discussion. While MBI, as noted above, considers that burnout has three dimensions, others consider burnout to have two or even one dimension; it is possible that burnout may have more than 3 dimensions. For example, Oldenburg Burnout Inventory considers only two dimensions of burnout out while Copenhagen Burnout Inventory (CBI) considers only one dimension of burnout.

Obviously, the disagreements about the definition and dimensions of burnout limit the study of effective interventions and have lead some to suggest that burnout perhaps does not exist as a separate entity on its own.