A New Diagnostic Tool to Detect Depression among Cancer People

A study develops a diagnostic tool to detect depression among cancer people. Various diagnostic methods have been put forward, but all of them use heterogeneous populations without focusing on cancer patients.

Why should we develop a diagnostic tool focusing on cancer patients?

First, it’s necessary to develop a method which can identify depression in cancer patients. The reason is that depression had a negative effect on cancer patients and these depressed cancer patients have a low quality of life and higher risk of death.

Second, previous methods, which use depressive symptoms and don’t focus on cancer patients, are not suitable to deal with depression identification in cancer people. The reason is that the depressive symptoms in cancer patients may be induced by depression and other factors, such as neoplastic progression and its treatment.

What is the diagnostic tool developed in this study?

A model indicating the probability of depression of patients with cancer is constructed using the scores of some of the Ham-D items.

Which items should be selected in the model?

We want to choose a model, which can be used as a diagnostic tool with both high sensitivity (when the cancer patients are truly depressive, the score of the items in the model should be high) and high specificity (when the cancer patients are not depressive, the score of the items in the model should be low) for the diagnosis of depression among cancer patients.

What is the procedure for model selection?

First, we sample four groups of individuals, that is, patients with major depression without cancer, normal-comparison individuals, caner patients with major depression, and cancer patients without major depression.

Second, we divide the 21 items into four groups. They are “positive items”, which are endorsed by depressed patients with cancer but not by cancer patients without major depression, “common items”, which are endorsed by both cancer patients with and without major depression, “neutral items”, which are endorsed by neither cancer patients with and without major depression, “negative items”, which are endorsed by cancer patients without major depression but not by depressed cancer patients.

Third, we fit five models. Model 1 use scores of positive items, model 2 use scores of positive and common items, model 3 use scores of positive and neutral items, model 4 use scores of positive, common and neutral items, model 5, which is reference model, use scores of all 21 items.

Fourth, we plot ROC curve, which is most popular measure of the accuracy of a diagnostic test for 5 models and find that model 2 is the best.

What’s the significance for this model selection procedure?

The model selection procedure is important because this procedure can serve as a prototype to generate valid instruments for the diagnosis of major depression, even other symptoms, in a certain populations.

Which items are included in the final model?

The final model contains “positive items”, which are 6 (late insomnia), 9 (agitation), 10 (anxiety, psychic), 18 (diurnal variation) and “common items”, which are 1 (depressed mood), 14 (genital symptoms).

What’s the significance of this diagnostic tool (final model)?

Since this model has high sensitivity and specificity, it can correctly detect depression in cancer patients. Thus, depression in cancer patients can be detected and treated at an early stage.


The researchers should ensure that adequate statistical and subject-matter expertise is both applied to the study. Moreover, researchers shouldn't predetermine the outcome when they apply statistical sampling.

Source: 

[1]Guo, Y., Musselman, D.L., Manatunga, A.K., Gilles, N., Lawson, K.C., Porter, M.R., McDaniel, J.S. and Nemeroff, C.B.
The Diagnosis of Depression in Patients with Cancer: a Comparative Approach

Psychosomatics, 47: 376-384, 2006. 

http://psy.psychiatryonline.org/cgi/reprint/47/5/376?maxtoshow=&HITS=10&hits=10&RESULTFORMAT=&author1=guo&andorexactfulltext=and&searchid=1&FIRSTINDEX=0&sortspec=relevance&resourcetype=HWCIT
[2]Geoffrey，Hamilton Depression Inventory HAM D.
http://www.carepaths.com/hamilton-depression-inventory-ham-d/

Author: Lijia Wang is a first year Ph.D. student in biostatistics department. She is interested in solving problems about public health using statistical methods. She wants to improve her oral and written English.

Naked and Exposed: Cancer Under the Microscope (Kylie Ainslie)

What is Cancer?: Getting to know the enemy

Cancer is a mysterious illness that seemingly comes in the dead of night, spreads fearlessly, and kills efficiently. For most, cancer is a poorly understood, deadly disease for which a cure remains elusive. In the last few decades researchers’ understanding of cancer has grown exponentially. Cancer is a family of diseases that begin with a small group of cells that grow and divide uncontrollably, and then invade the body via a complex, multistep process. At the root of cancer development are mutations, changes in the genetic code (DNA) resulting from errors in DNA replication, of a subgroup of cells. These mutations alter the normal functions of the cell allowing for better survival. Eventually, those cells best fit for survival acquire more mutations enabling them to survive even better.

Hanahan and Weinberg identify six capabilities enabling tumor[i] formation and spread of cancer cells throughout the body. The six capabilities, or hallmarks, are:

1.     Uncontrolled cell growth and division

2.     Inactivation of tumor suppressing mechanisms

3.     Evasion of programmed cell death

4.     Unlimited replication

5.     Formation of new blood vessels

6.     Ability to invade surrounding tissues and spread throughout the body (metastasis).

Once a cell acquires all six hallmarks, it is classified as cancerous. Hallmarks are not necessarily acquired in the order listed above.

           

http://www.cancer.gov/cancertopics/cancerlibrary/what-is-cancer

            The first, and arguably most fundamental, hallmark of cancer cells is uncontrolled cell proliferation (growth and division). Normal cells contain controls that prevent rampant cell division, but cancer cells have developed mutations that disrupt those cellular controls. Similarly, normal cells also possess other mechanisms that suppress the acquisition of hallmarks. The inactivation of these tumor-suppressing mechanisms, enabling mutations to occur, is the second hallmark.

            When cells become old or sustain irreversible stress, such as extensive DNA damage, cell death is initiated. DNA damage can increase the rate of mutation when cell division occurs, so the initiation of cell death removes the threat of future mutations. Cancer cells develop methods to circumvent cell death, which allows the cells to continually divide and increase the chance of acquiring other hallmarks.

            Normal cells can only replicate their DNA a fixed number of times. However, cancer cells must be able to replicate an unlimited number of times to develop large tumors.

            Cancer cells grow and divide at abnormally high rates. To maintain such high activity requires nutrients from blood vessels. To meet excessive energy needs, cancer cells create new blood vessels (angiogenesis). New blood vessels are normally only created during early development and wound healing, but cancer cells can turn the signals to create new vessels back on.

            The sixth hallmark is the ability of cancer cells to invade surrounding tissues and metastasize, spread throughout the body. This hallmark makes cancer so deadly. Cells in the primary tumor break free, enter nearby blood vessels, travel through the vessels, exit the vessels farther downstream, implant in distant tissues, and finally acquire mutations that allow for the formation of secondary tumors in distant tissues. Not all cells that travel from the primary tumor form secondary tumors. Though most cancer cells are eliminated during the journey, those with the most advantageous mutations will form secondary tumors.

(Hanahan and Weinberg 2011)


What now?

            The multitude of research exploding worldwide into cancer mechanisms, characteristics, and therapeutics has increased the ability to detect, treat, and to some extent prevent cancer. For the average person, however, cancer is still shrouded in mystery. Cancer is very complex, but it is important for the general population to understand the basics of cancer causes, progression, and prevention. There has been significant progress in the development of new cancer therapeutics that target hallmark mechanisms (bench to bedside translation). Despite this progress, there is a disconnect between the labs teeming with researchers and the information available to the general population. How can individuals access information about cancer? Doctors are too busy, the internet is a sea of legitimate and bogus information, computers are intimidating to older generations who are at risk for cancer now. Cancer can run amuck in humans long before symptoms appear. Often, cancer is diagnosed long past the stage where any of the myriad of drugs available can be beneficial. The first step in the war on cancer is education, getting to know the enemy.

topics.time.com

Information is power!

            “Cancer is a disease of aging. If you live long enough you will get cancer” (Dr. Doetsch, pers. comm.). Cancer may be inevitable, but the goal is to keep it at bay long enough to live a long, healthy life. Screening for cancer is an excellent way to detect cancer early. Some screening techniques are most effective under certain conditions. For example, mammography, used to screen for breast cancer, is most effective in women over 50 (Mukherjee, 2010). However, patients with a family history of the disease have an increased risk, and should be screened earlier. Women with a family history of breast cancer should be screened as early as in their 30s. Ethnicity also plays a role in cancer risk. African American women have a higher incidence of cancer than their white counterparts. It's important that women understand when they should be screened. Efforts to increase dissemination of information by putting legitimate information on the internet, mailing information to women at risk, offering informational seminars on screening and risks, and opening information hotlines, a number women can call to talk to a medical professional to have their questions answered, should be initiated.

            Screening, however is not free, and often requires patients to go to special clinics. Individuals who live far from clinics or who cannot afford screening are much less likely to be screened. "The United States is the only developed country without a national healthcare system" (Dr. L. Wilke, pers. comm.). In a perfect world, Congress would stop bickering and pass a national healthcare plan that provides low cost or free screening to at risk women. In the mean time, mobile screening centers offering screening for little or no cost should be dispersed in areas without nearby clinics.

            While screening has many benefits, it also poses an ethical dilemma. Why not screen everyone? As technology improves, screening can be performed earlier. "Screening earlier doubles the risk of false positives" (Dr. L. Wilke, pers. comm.). If screening technology is employed too early there is increased risk of false detection, where a person without cancer is diagnosed with cancer. False diagnosis can lead to emotional stress and costly, often invasive, additional tests and treatments. The harm of false diagnosis cements the necessity of programs designed to educate people on appropriate screening.

The implementation of campaigns to educate the population on screening together with initiatives to provide better access to screening can greatly reduce the incidence of cancer related deaths.

References:
Hanahan, D. and R. Weinberg. 2011. Hallmarks of Cancer: The Next Generation. Cell 144:646-674.

Mukherjee, S. 2010. The emperor of all maladies: A biography of cancer. New York, NY: Scribner.

---

[i] In this article, “tumor” refers to malignant tumor. Benign tumors are not considered cancerous because they do not invade surrounding tissues and spread throughout the body (i.e. they do not possess all six hallmarks). 

Kylie Ainslie is a first year PhD student in the department of Biostatistics and Bioinformatics at Emory University. She hopes to apply biostatistical methods to cancer research. When not involved in scholastic endeavors, Kylie enjoys running long distances in weather most normal people would elect to stay inside during and coaching softball to a gaggle of mismatched houligans.

It's fun to stay at the Y-M-C-A….!

Really…you want to order that extra-large fries? Why not buy a YMCA membership instead? It’ll probably be more worth your while considering the skyrocketing number of people that have pre-diabetes these days. What is that huge number you ask – well, it’s over 60 million Americans! YES, you read it right. 60 million. That also means 60 million people who are at risk of a heart attack, stroke, blindness or other obesity-related health problems.

The YMCA is doing something great - it has partnered up with Indiana University School of Medicine to deploy a real-world adaptation of the Diabetes Prevention Program. The YMCA’s Diabetes Prevention Program is meant to help people learn about and adopt healthy eating and exercise habits that have been proven to reduce the risk of developing Type 2 diabetes.  The program gives people with pre-diabetes support and encouragement from both a trained lifestyle coach, and fellow classmates to develop a plan for improving and maintaining overall well-being.

To potentially be eligible to join this program, one should have a body mass index higher than 24, more than 2 diabetes risk factors (which include age, personal history, family history, race and ethnicity, weight and waist measurement, smoking, physical activity, diet and alcohol consumption) and a blood glucose level within a specified range. 6 months after the pilot program was deployed, it was found that the 92 participants, who were more often woman of non-white race, had lost 5.7 kgs on average compared to only 1.8 kgs in control participants. Cholesterol levels of participants also dropped significantly compared to the control group. These differences were sustained for 12 months.

What are some things you should take away from this pilot program?

1)   Lifestyle modification is very effective to prevent or delay the onset of diabetes. People at high risk for developing diabetes were able to achieve and maintain a reduction in body weight and a significant reduction in total cholesterol levels.

2)   The YMCA is a great place for wide-scale spread of this low-cost approach to lifestyle diabetes prevention! Soon this program may be offered at a YMCA near you. So keep your eye out for it. Go ahead, get involved, and improve your health today!

Quote from an expert:

"We are leveraging our national health care resources, the YMCA's and Walgreens' presence in local communities, our combined wellness expertise and the experience of two innovative, proven pilot programs to help people make lifestyle changes to prevent or control diabetes."

-Stephen Hemsley, president and CEO of UnitedHealth Group

Rita Wakim, MA., is interested in diabetes research: prevention and health outcomes. She is currently working towards a doctoral degree in Health Policy and Management at Emory University.

                                    

Reference:

Ronald T. Ackermann, MD, et al " Translating the Diabetes Prevention Program into

the Community The DEPLOY Pilot Study." American Journal of Preventive Medicine (2008): 357-363.

Pass the Cheese, Please! - Miriam Abouelnasr

FreeFoto.com

It has been nearly a year since the Institute of Medicine (IOM) issued a new report on Vitamin D and Calcium.  The report found that calcium and vitamin D are so important for bone health that new recommendations for the public were made. 

• Men and women under the age of 50 need 1,000 milligrams (mg) of calcium and 600 international units (IU) of vitamin D per day. 
• Women age 50 and older need 1,200 mg calcium and 600 IU vitamin D per day and women age 70 and older need 1,200 mg of calcium and 600 IU of vitamin D per day.
• Men over the age of 50 need 1,000 mg calcium and 600 IU per day and men over the age of 70 need 1,200 mg of calcium and 800 IU of vitamin per day.

The recommendations are different for pregnant women, children, and infants so be sure to consult your doctor or dietitian regarding supplement use.

To give you an idea of how much calcium and vitamin D are in food, one cup of milk has about 550 mg of calcium and 120 IU of vitamin D.  Calcium is mainly in dairy, including milk and cheese, but it can also be found in non-animal sources, such as broccoli, some breakfast cereals, juice, and soy milk.  Our bodies are able to make vitamin D as long as we have access to sunlight.  Food sources of vitamin D include fatty fish (like salmon, tuna, and sardines), dairy, eggs, and some breakfast cereals.  Be sure to check out the food label, as both of these nutrients are listed there.  Supplements, such as multivitamin pills, can be a good source of calcium and vitamin D as well, but only if you are not getting enough from your diet. 

Despite the importance of this vitamin, The IOM also determined that certain groups of people are at risk for low blood levels of vitamin D.  These groups include people who live in northerly latitudes, people who live in intuitions (like prisons and mental health facilities), and people with dark skin.  This is because these three groups of people may have less access to sunlight.

Just when you were thinking that more is better, there are upper levels for each calcium and vitamin D.  So, if you eat more than the maximum level, which is 2,000 – 2,500 mg calcium and 4,000 IU vitamin D, it can actually have a negative impact on your health.  Bottom line, don’t go overboard!

Quote from an expert:

“The new recommendations on Vitamin D are conservative and target vitamin D doses to maintain health.”

-Nida Shaikh, MS, RD, LD

Miriam Abouelnasr MS, RD, LD spent a year at Grady Memorial Hospital in Atlanta, Georgia working for the Women, Infants, and Children (WIC) Program.  She is currently a registered dietitian and working towards her PhD in nutrition at Emory University in Atlanta.  She enjoys dairy, but especially chocolate soy milk!

                                    

Reference:

Ross, Catherine A., et al "The 2011 Dietary Reference Intakes for Calcium and Vitamin D: What Dietetics Practitioners Need to Know." Journal of the American Dietetic Association (2011): 524-527.

Room for Improvement: Learning the Subtle Signs of Stroke (Margarethe Goetz)

Which of these might be a stroke?

A 67 year-old woman with sudden right arm weakness and difficulty speaking.

A 25 year-old man complains of a sudden severe headache.

A 58 year-old man awakes with numbness and tingling of the left side of his body.

A 45-year-old woman suddenly cannot see things on her left side.

Each of these cases is a stroke until proven otherwise. Unfortunately, a study done by the Departments of Neurology and Emergency Medicine at the University of Cincinnati suggests that the last two individuals are less likely to be recognized as a potential stroke and get a timely trip to the Emergency Room by ambulance. Bystanders and stroke patients miss many stroke symptoms. Moreover, some stroke patients are unable to recognize their own symptoms or are incapacitated, requiring witnesses to help them.

What is a stroke?

Stroke is one of the leading causes of death and disability in the United States. Not all strokes are the same; they can have different underlying causes. The majority of strokes, ischemic strokes, happen because blood clots block blood flow through arteries to portions of the brain. A smaller number of strokes, hemorrhagic strokes, are due to bleeding into or around the brain. In either case, brain tissue can be irreversibly damaged. Stroke symptoms arise, within minutes, when a part of the brain is starved of oxygen and nutrients and no longer functions. For instance, when a stroke patient has a weak arm, it’s because the part of the brain that controls the arm is dying. 

Why does time to treatment matter?

Often, early evaluation and treatment can reverse or reduce the damage caused by a stroke. The clot busting drug rt-PA can be given to ischemic stroke patients to break up clot in the affected artery and restore blood flow. Unfortunately, the window for treatment is only 4.5 hours from symptom onset. Transportation by a 911 ambulance can speed arrival to the ER and increase the likelihood of receiving rt-PA. This means that a suspected stroke patient must be identified quickly, receive transportation by EMS to a hospital, be evaluated and treated within 4.5 hours.

In the less common case of a hemorrhagicstroke, time may be critical, even though clot-busting drugs are not indicated. In the worst cases, patients might need medications to correct blood clotting disorders, neurosurgical treatment or repair of a ruptured brain aneurysm. Again, time is of the essence for a stroke patient. The faster that definitive treatment is given, the more brain tissue can be saved.

Back to the study…

In the report from the Greater Cincinnati/Northern Kentucky Stroke Study (GCNKSS), 2975 independent living stroke cases were identified from records for the year 1999. Sixty-one percent of cases were ischemic strokes, 11% were hemorrhagic strokes and 28% were transient ischemic attacks, or “ministrokes”. Only 40% of patients were transported by EMS to the ER. Symptoms associated with EMS use were weakness, decreased level of consciousness, speech difficulties, and dizziness. Emergency Medical Services were less likely to be contacted for numbness and vision problems, while headache was not associated with EMS contact.

It may be surprising that numbness and vision problems were not reasons to contact EMS. However, according to neurointensivist Steve Potter MD, PhD, “People frequently ignore vision changes because their subtlety can easily be brushed off.“ Neurointensivists are neurologists with additional training in ICU medicine and treat stroke patients daily. Numbness can also be a nonspecific symptom. “A patient may ascribe a numb arm in the morning to sleeping position and decide to wait the symptom out. When numbness persists, they contact their primary care physician who directs them to the hospital. Unfortunately, by then it’s usually too late to treat with t-PA.”

What should we do?

The most important thing to do when a stroke is suspected, is to act and call 911. Though other diseases can resemble a stroke, the only way to know for sure is medical evaluation. Subtle stroke symptoms pose a challenge for public education.  As the study authors suggested, public education campaigns should address stroke symptoms and also emphasize the importance of numbness, vision changes and severe headache. Suspicion of stroke should be linked with an action plan to call 911. Theoretically, encouraging utilization of EMS services might strain 911 systems. Ambulances might be unavailable to respond to other emergencies while transporting patients who may not actually be having strokes. In reality, though, too many people hesitate to call 911. The small potential increase in EMS utilization would be far outweighed by the potential reduction in long-term disability costs due to stroke. A suspected stroke is always adequate cause to request an ambulance. Remember, time saves brain and the next person who needs help might be a neighbor, friend, family member or you. Don’t be afraid to call 911.

Source: Kleindorfer D, et al. Am J Emerg Med. 2010 June; 28(5): 607-612. 

Margarethe Goetz PA-C, MMSc

An overcaffeinated neurocritical care Physician Assistant, former paramedic, and self-proclaimed geek, taking a hiatus from real life to study public health in hopes of keeping the public healthy and out of her ICU.

Over-the-counter and under-the-radar: use of NSAIDs among people with kidney disease is common and could be harmful

NSAIDs, or non-steroidal anti-inflammatory drugs, are widely available over-the-counter, including ibuprofen (Advil™, Motrin™), naproxen (Aleve™, Anaprox™), and aspirin. These medications are primarily used as pain relievers (“analgesics”) and fever reducers. Additionally, many multi-drug formulations, like medicines for colds and menstrual symptoms, also contain NSAIDs.

Many NSAIDs are sold over-the-counter.

It is easy to forget that medications available over-the-counter are not without side effects and that they may not be safe for everyone. A recent community-based study (1) showed that NSAID use was common and that those with kidney disease were twice as likely to use NSAIDs frequently than those without kidney disease. This is despite the recommendation of the National Kidney Foundation (NKF) that people with kidney disease avoid NSAIDs because the effects of renal clearance of these drugs may be associated with kidney injury and progression of kidney disease. [Note that acetaminophen (Tylenol™) does not have the same type of clearance and is not considered risky in those with kidney disease.]

NSAIDs interact with several prescription drugs.

Additionally, NSAIDs may lessen the effectiveness of prescription drugs frequently taken by those with kidney disease, including angiotensin-converting enzyme (ACE) inhibitors, angiotensin receptor blockers (ARBs), and diuretics, all of which are taken to control blood pressure and prevent progression of disease. According to Vanessa Grubbs, MD, a nephrologist with the University of California, San Francisco, and co-author on the paper, “Primary care clinicians and doctors who prescribe medicine for pain management need to be aware of the potential interactions of NSAIDs with ACE inhibitors, ARBs, and loop diuretics.”

About 26 million people in the United States have early stages of kidney disease and >500,000 are currently treated with dialysis or have a kidney transplant because their kidneys have failed. Costs for kidney disease care make up about one-third of the Medicare budget. Thus, preventing and slowing the progression of CKD in the United States is essential, and educating patients and providers about the potential risks of NSAIDs is a way to improve patient outcomes.

What can you, as a patient, do about this potential risk?

First, know your risk for kidney disease. Other studies (2) have shown that most people with kidney disease are unaware of their disease. Kidney disease is often “silent” (=no symptoms) until it has progressed to late stages. Thus, knowing your risk allows you to ask your doctor for simple tests (serum creatinine and urine protein) that can assess possible damage to or reduced function of the kidneys. The most common risk factors for kidney disease are:

1. Diabetes

2. Hypertension

3. African-American, Hispanic, Pacific Islander, or Native American race/ethnicity

4. Family history

5. Older age

6. Inherited and autoimmune conditions such as glomerulonephritis and lupus

Second, if you have, or at high risk for, kidney disease, don’t assume that a drug is safe for you because it is available over-the-counter. There are explicit warnings on NSAIDs bottles about the increased risk of stomach ulcers/bleeding and cardiovascular events, but no such warnings regarding risk for kidney injury and disease progression appear on the bottle, despite calls for this labeling from the NKF >10 years ago. For any over-the-counter drug, read the entire label, including that insert inside the box that most of us throw away. You should consider asking your doctor about any drug or supplement you take over-the-counter, but specifically any that contain warnings about kidney or “renal” risks or describe the drug as having “renal clearance.”

What can health care providers do?

First, health care providers should test their high-risk patients regularly for kidney disease and talk to their patients about their risk. NSAIDs should be prescribed only as needed in those with or at high risk and after careful weighing of the risks and benefits. For example, a patient with debilitating arthritis may need pain relief for an acceptable quality of life, despite the potential risks.

Second, providers should carefully assess the use of over-the-counter NSAIDs in their patients. While patients often list the drugs they are taking as part of their visit, they may not consider over-the-counter NSAIDs as “drugs” or may forget about drug formulations that they take intermittently, such as cold medications. Also, some patients with low health literacy or problems with their vision may not be able to recall names of medications, which could lead to an ethical issue, if such vulnerable patients receive less-than-optimal advice. Providers may want to consider instead presenting a series of photos of various types of medication packaging that  contain NSAIDs so that the patient can identify the drugs they’ve taken rather than having to list the names of the medications.

About the author

Laura Plantinga, Sc.M., is a researcher whose interests include kidney disease awareness and outcomes. She is currently working on a doctoral degree in epidemiology at Emory University and setting a world record for oldest graduate student.

References
1. Plantinga L, Grubbs V, Sarkar U, Hsu CY, Hedgeman E, Robinson B, Saran R, Geiss L, Burrows NR, Eberhardt M, Powe N; CDC CKD Surveillance Team. Nonsteroidal anti-inflammatory drug use among persons with chronic kidney disease in the United States. Ann Fam Med. 2011;9(5):423-30.
2. Plantinga LC, Tuot DS, Powe NR. Awareness of chronic kidney disease among patients and providers. Adv Chronic Kidney Dis. 2010 May;17(3):225-36.

Images courtesy of Google images

A Desert within a Desert: NYC’s Green Cart Program Fails to Reach Neediest Areas (Brooke Hixson)

NYC’s Green Cart program, designed to increase the availability of fresh produce in disadvantaged neighborhoods, has not been successful in reaching those the most in need. Researchers at Montefiore Medical Center, a Bronx hospital, investigated the Green Cart program, looking at how well the carts were fulfilling their intended purpose of selling fresh produce in areas where fruits and vegetables were otherwise unavailable. They found the carts were unevenly distributed around the Bronx with clusters of carts in some areas and no carts in others.

A woman buys produce at a Bronx Green Cart

The Green Cart program began in 2008 when the NYC City Council approved a measure allowing mobile food carts selling fresh produce to operate in areas with traditionally low consumption of fresh fruits and vegetables (often caused by a lack of supply in local stores). Neighborhoods where fresh produce and other healthy foods are difficult to find are often referred to as “food deserts.” Green Carts were touted by anti-hunger and child-advocacy groups as one solution to food deserts in poorer areas of NYC.

While the NYC Department of Health backed the Green Cart program and administers the permits, they also acknowledged that it was not a comprehensive solution to community health issues such as obesity and diabetes. Dr. Thomas Frieden, then city health commissioner and current CDC Director, expressed measured support, saying, "This is not going to end the obesity epidemic, but it is an important step to increase access to healthy food in the communities that need it most."

Despite fierce opposition from local bodega owners, support from the NYC DOH and a $1.5 million grant to provide microloans to cart vendors has resulted in Green Carts appearing across all five boroughs. However, the Green Carts must follow specific guidelines on where they can sell (only in food deserts determined by the NYC DOH) and what they can sell (only raw unprocessed fruits and vegetables – no peeling, chopping, etc.). Since the program's implementation in 2008, public reaction has been generally positive with some carts operating 24 hours/day, 7 days/week to meet demand.

Researchers looking at Green Carts in the Bronx, however, found the Green Carts tended to cluster in "hotspots" around hospitals, schools, subway stops, libraries, and the Bronx Zoo. As a result, some of the neighborhoods in the greatest need of fresh produce still did not have local access. Thus, even within an area generalized as a food desert, some areas are “drier” than others. Researchers also found a few carts operating outside the legal zone in areas that are not considered food deserts.

Maps of Green Cart Locations in the Bronx

Most disturbingly, researchers found about 10% of the carts were selling sugary drinks and cookies, defeating the entire purpose of the carts. Although selling anything other than fresh produce is expressly forbidden (and results in a $550 fine), there appears to be little oversight on the street.

During this time of skyrocketing obesity and diabetes rates, any effective intervention that reduces the risk of these diseases is important to invest in and to implement correctly. If NYC can work out the kinks in their Green Cart program and get its most at-risk residents to eat more fresh produce, the program is likely to expand to other metropolitan areas across the country. Government officials need to provider stricter oversight of current Green Carts’ inventory. Program coordinators should work with community groups to create local demand in Green Carts deserts and to enlist local residents to become vendors. Green Carts should also be designed to accommodate electronic benefit transfers (i.e., food stamps). Finally, public health officials must continue to work with established community businesses (such as bodegas) to encourage them to supply their communities with affordable fresh produce rather than relying on Green Carts alone to provide much needed nutrition in food deserts.


Brooke Hixson has worked in various aspects public health for almost 10 years. She is currently a doctoral student in Biostatistics at Emory University studying spatial analysis. She enjoys both fresh produce and NYC.


Source: Lucan SC, Maroko A, Shanker R, Jordan WB. Green Carts (Mobile Produce Vendors) in the Bronx-Optimally Positioned to Meet Neighborhood Fruit-and-Vegetable Needs? J Urban Health 2011 Oct;88(5):977-81.

A Social Experiment

You are where you live. A new study shows that low-income individuals who move to high-income neighborhoods have less obesity and better blood sugar control than individuals who stay in low-income neighborhoods. Past studies have shown that neighborhoods impact their residents’ health, but this is the first to show that changing from one kind of neighborhood to another can positively benefit an individual, even if most other things about that person’s life stay the same.

In the October 20^th issue of the New England Journal of Medicine, Dr. Jens Ludwig, et al. published a paper on the health effects observed in the Department of Housing and Urban Development (HUD)’s Moving to Opportunity (MTO) demonstration project. MTO was a case-control study designed to measure the role that neighborhoods play in health. Participants in MTO were randomly selected Section 8 housing recipients in high-poverty neighborhoods in five major US cities. They were divided into three groups. The first group was given vouchers to allow them to move to a new neighborhood with a low level of poverty. The second group was given vouchers to allow them to move to a new neighborhood that was not necessarily different socioeconomically. The third group was not given vouchers. The health of individuals in all three groups was tracked over time.

Those participants who received vouchers to move to higher-income neighborhoods and chose to move were less likely to be obese and less likely to have uncontrolled diabetes than those who did not receive vouchers, even though the two groups were initially very similar. This is an important finding because it highlights the way that where one lives impacts one’s health and that moving can change that impact. Though the reductions in obesity and diabetes were small (around 2-3% overall), they were significant—few other interventions even come close. As Dr. Thomas W. McDade, a coauthor  of the study notes, “The magnitude of the effects of the experiment are striking, and are comparable in size to the effects on diabetes we see from targeted lifestyle interventions or from providing people with medication to prevent the onset of diabetes.”

However, it’s important to keep in mind that the study is, at its most fundamental, a social experiment. HUD does not have the resources or ability to incentivize all Section 8 housing recipients in high-poverty neighborhoods to move to more healthful areas. Even if they did, there are not enough housing options for that to be a feasible option. So, if it cannot be widely implemented, why does this matter, other than to satisfy the curiosity of public health researchers and urban developers? This study opens the door to asking what it is that makes low-poverty neighborhoods that much healthier. Past studies have shown that some features of many low-poverty neighborhoods, like lower crime rates, better access to fresh fruits and vegetables, and parks may have positive effects on wellbeing. MTO is a chance to reexamine these factors and see if there are others, like transportation options and school quality, which might also play a role. Determining which of these are effective can help guide city planners in improving existing high-poverty neighborhoods to make them healthier, even if they do not become wealthier.

This study also makes a case for adding more mixed-income housing in low-poverty neighborhoods. While it is important to not abandon high-poverty neighborhoods (hence the role of city planners and ongoing urban improvement), incorporating more Section 8 housing into low-poverty areas may serve as a stop-gap. Ethically, financially, and logistically, it is not possible to clear out all high-poverty neighborhoods and relocate former residents to low-poverty neighborhoods in the name of public health, but providing individuals with options to live in more mixed-income areas may show a benefit.

Sources:

Anyaso, Hilary Hurd. “From High to Lower Poverty.” Northwestern University News Center. Accessed Nov. 7, 2011 http://www.northwestern.edu/newscenter/stories/2011/10/poverty-study-mcdade.html

Ludwig, Jens, et al. Neighborhoods, Obesity, and Diabetes—A Randomized Social Experiment. New England Journal of Medicine 2011; 365: 1509-1519. October 20, 2011.
Wheeler, Helen Rippier. "Berkeley's Housing Authority Administers Section 8, Public Housing." Accessed Nov. 7, 2011 http://www.berkeleydailyplanet.com/photos/05-14-04/5%253A14%2520rectangle.jpg

Author:

Kira Newman is a second year MD/PhD student beginning the PhD portion of her education in epidemiology.  Her research interests focus on the nexus between environment and health.  Kira brings a broad background to translational research including primary research in historical epidemiology and practical epidemiology experiences at CDC and state levels.  Biking, climbing, and scavenging free food are her passions.