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Biomedical subjects

Farzad Mostashari

Publications and source records attributed to Farzad Mostashari.

At least 19 recordsLinked to original sources
PubMed2007

Multivariate scan statistics for disease surveillance.

In disease surveillance, there are often many different data sets or data groupings for which we wish to do surveillance. If each data set is analysed separately rather than combined, the statistical power to detect an outbreak that is present in all data sets may suffer due to low numbers in each. On the other hand, if the data sets are added by taking the sum of the counts, then a signal that is primarily present in one data set may be hidden due to random noise in the other data sets. In this paper, we present an extension of the spatial and space-time scan statistic that simultaneously incorporates multiple data sets into a single likelihood function, so that a signal is generated whether it occurs in only one or in multiple data sets. This is done by defining the combined log likelihood as the sum of the individual log likelihoods for those data sets for which the observed case count is more than the expected. We also present another extension, where the concept of combining likelihoods from different data sets is used to adjust for covariates. Using data from the National Bioterrorism Syndromic Surveillance Demonstration Project, we illustrate the new method using physician telephone calls, regular physician visits and urgent care visits by Harvard Pilgrim Health Care members cared for by Harvard Vanguard Medical Associates, a large multi-specialty group practice in Massachusetts. For upper and lower gastrointestinal (GI) illness, there were on average 20 telephone calls, nine urgent care visits and 22 regular physician visits per day. The strongest signal was generated by a single data set and due to a familial outbreak of pinworm disease. The second and third strongest signals were generated by the combined strength of two of the three data sets.

Boston↗
PubMed2006

Discordance between sexual behavior and self-reported sexual identity: a population-based survey of New York City men.

BACKGROUND: Persons reporting sexual identity that is discordant with their sexual behavior may engage in riskier sexual behaviors than those with concordant identity and behavior. The former group could play an important role in the spread of sexually transmitted diseases. OBJECTIVE: To describe discordance between self-described sexual identity and behavior among men who have sex with men and associations between identity-behavior and risk behaviors. DESIGN: Cross-sectional, random digit-dialed telephone survey of health status and risk behaviors. SETTING: New York City. PARTICIPANTS: Population-based sample of 4193 men. MEASUREMENTS: Concurrent measures of sexual identity and sexual behaviors, including number and sex of sex partners, condom use during last sexual encounter, and recent testing for HIV infection. Sex partner information was ascertained in a separate section from sexual identity; all participants were asked about the number of male sex partners and then were asked about the number of female sex partners in the past year. RESULTS: Of New York City men reporting a sexual identity, 12% reported sex with other men. Men who had sex with men exclusively but self-identified as heterosexual were more likely than their gay-identified counterparts to belong to minority racial or ethnic groups, be foreign-born, have lower education and income levels, and be married. These men were more likely than gay-identified men who have sex with men to report having only 1 sexual partner in the previous year. However, they were less likely to have been tested for HIV infection during that time (adjusted prevalence ratio, 0.6 [95% CI, 0.4 to 0.9]) and less likely to have used condoms during their last sexual encounter (adjusted prevalence ratio, 0.5 [CI, 0.3 to 1.0]). LIMITATIONS: The survey did not sample groups that cannot be reached by using residential telephone services. CONCLUSIONS: Many New York City men who have sex with men do not identify as gay. Medical providers cannot rely on patients' self-reported identities to appropriately assess risk for HIV infection and sexually transmitted diseases; they must inquire about behavior. Public health prevention messages should target risky sexual activities rather than a person's sexual identity.

Adolescent↗
PubMed2006

Health care access and utilization among women who have sex with women: sexual behavior and identity.

Past research has shown that women who either have sex with women or who identify as lesbian access less preventive health care than other women. However, previous studies have generally relied on convenience samples and have not examined the multiple associations of sexual identity, behavior and health care access/utilization. Unlike other studies, we used a multi-lingual population-based survey in New York City to examine the use of Pap tests and mammograms, as well as health care coverage and the use of primary care providers, among women who have sex with women and by sexual identity status. We found that women who had sex with women (WSW) were less likely to have had a Pap test in the past 3 years (66 vs. 80%, p<0.0001) or a mammogram in the past 2 years (53 vs. 73%, p=0.0009) than other women. After adjusting for health insurance coverage and other factors, WSW were ten times [adjusted odds ratio (AOR), 9.8, 95% confidence interval (CI), 4.2, 22.9] and four times (AOR, 4.0, 95% CI 1.3, 12.0) more likely than non-WSW to not have received a timely Pap test or mammogram, respectively. Women whose behavior and identity were concordant were more likely to access Pap tests and mammograms than those whose behavior and identity were discordant. For example, WSW who identified as lesbians were more likely to have received timely Pap tests (97 vs. 48%, p<0.0001) and mammograms (86 vs. 42%, p=0.0007) than those who identified as heterosexual. Given the current screening recommendations for Pap tests and mammograms, provider counseling and public health messages should be inclusive of women who have sex with women, including those who have sex with women but identify as heterosexual.

Adolescent↗
PubMed2005

Diarrheal illness detected through syndromic surveillance after a massive power outage: New York City, August 2003.

OBJECTIVES: We investigated increases in diarrheal illness detected through syndromic surveillance after a power outage in New York City on August 14, 2003. METHODS: The New York City Department of Health and Mental Hygiene uses emergency department, pharmacy, and absentee data to conduct syndromic surveillance for diarrhea. We conducted a case-control investigation among patients presenting during August 16 to 18, 2003, to emergency departments that participated in syndromic surveillance. We compared risk factors for diarrheal illness ascertained through structured telephone interviews for case patients presenting with diarrheal symptoms and control patients selected from a stratified random sample of nondiarrheal patients. RESULTS: Increases in diarrhea were detected in all data streams. Of 758 patients selected for the investigation, 301 (40%) received the full interview. Among patients 13 years and older, consumption of meat (odds ratio [OR]=2.7, 95% confidence interval [CI]=1.2, 6.1) and seafood (OR=4.8; 95% CI=1.6, 14) between the power outage and symptom onset was associated with diarrheal illness. CONCLUSIONS: Diarrhea may have resulted from consumption of meat or seafood that spoiled after the power outage. Syndromic surveillance enabled prompt detection and systematic investigation of citywide illness that would otherwise have gone undetected.

Adolescent↗
PubMed2005

Evaluation of school absenteeism data for early outbreak detection, New York City.

BACKGROUND: School absenteeism data may have utility as an early indicator of disease outbreaks, however their value should be critically examined. This paper describes an evaluation of the utility of school absenteeism data for early outbreak detection in New York City (NYC). METHODS: To assess citywide temporal trends in absenteeism, we downloaded three years (2001-02, 2002-03, 2003-04) of daily school attendance data from the NYC Department of Education (DOE) website. We applied the CuSum method to identify aberrations in the adjusted daily percent absent. A spatial scan statistic was used to assess geographic clustering in absenteeism for the 2001-02 academic year. RESULTS: Moderate increases in absenteeism were observed among children during peak influenza season. Spatial analysis detected 790 significant clusters of absenteeism among elementary school children (p < 0.01), two of which occurred during a previously reported outbreak. CONCLUSION: Monitoring school absenteeism may be moderately useful for detecting large citywide epidemics, however, school-level data were noisy and we were unable to demonstrate any practical value in using cluster analysis to detect localized outbreaks. Based on these results, we will not implement prospective monitoring of school absenteeism data, but are evaluating the utility of more specific school-based data for outbreak detection.

Absenteeism↗
PubMed2005

Colon cancer screening practices in New York City, 2003: results of a large random-digit dialed telephone survey.

BACKGROUND: New York City (NYC) has one of the highest concentrations of gastroenterologists in the country, yet only 33% of colorectal cancers in NYC are diagnosed early, and approximately 1500 New Yorkers die from colorectal cancer each year. METHODS: Using data from a large, local, random-digit dialed telephone survey (n = 9802), the authors of the current study described types of colorectal cancer screening modalities and characteristics of adults undergoing screening within a recommended timeframe. Multivariate analyses were used to examine demographic, behavioral, socioeconomic, and neighborhood-level predictors of screening participation, with particular attention to factors associated with colonoscopy, the recommended screening modality in NYC. RESULTS: Fifty-five percent of NYC adults aged > or = 50 years reported a recent colorectal cancer screening test, and 42% reported a colonoscopy within the past 10 years. After multiple statistical adjustments, groups with the lowest likelihood of screening were the poor (odds ratio [OR], 0.66; 95% confidence interval [CI], 0.53-0.83) and uninsured (OR, 0.31; 95% CI, 0.20-0.48), as well as Asians (OR, 0.46; 95% CI, 0.29-0. 72), and current smokers (OR, 0.62; 95% CI, 0.50-0.78). Colonoscopy was less frequently reported by non-Hispanic Black New Yorkers and by women; both groups reported higher use of fecal occult blood tests. Less than 10% of adult New Yorkers reported a sigmoidoscopy in the past 5 years. CONCLUSIONS: Low screening uptake in NYC leaves nearly 1 million New Yorkers, particularly poor and uninsured adults, at risk for undetected colorectal cancer. Colonoscopy screening programs in NYC should address health care and socioeconomic barriers and target racial and ethnic minorities and women.

Aged↗
PubMed2005

Cardiac events in New Jersey after the September 11, 2001, terrorist attack.

The higher stress associated with the World Trade Center (WTC) attacks on September 11, 2001, may have resulted in more cardiac events particularly in those living in close proximity. Our goal was to determine if there was an increase in cardiac events in a subset of emergency departments (EDs) within a 50-mi radius of the WTC. We performed a retrospective analysis of consecutive patients seen by ED physicians in 16 EDs for the 60 days before and after September 11 in 2000-2002. We determined the number of patients admitted to an inpatient bed with a primary or secondary diagnosis of acute myocardial infarction (MI) or tachyarrhythmia. In each year, we compared patient visits for the 60 days before and after September 11 using the chi-square statistic. For the 360 days during the 3 years, there were 571,079 patient visits in the database of which 110,766 (19.4%) were admitted. Comparing the 60 days before and after September 11, 2001, we found a statistically significant increase in patients with MIs (79 patients before versus 118 patients after, P =.01), representing an increase of 49%. There were no statistically significant differences for MIs in 2000 and 2002 and in tachyarrhythmias for all three years. For the 60-day period after September 11, 2001, we found a statistically significant increase in the number of patients presenting with acute MI but no increase in patients admitted with tachyarrhythmias.

Emergency Service, Hospital↗
PubMed2005

Smoking practices in New York City: the use of a population-based survey to guide policy-making and programming.

To inform New York City's (NYC's) tobacco control program, we identified the neighborhoods with the highest smoking rates, estimated the burden of second-hand smoke exposure, assessed the early response to state taxation, and examined cessation practices. We used a stratified random design to conduct a digit-dialed telephone survey in 2002 among 9,674 New York City adults. Our main outcome measures included prevalence of cigarette smoking, exposure to second-hand smoke, the response of smokers to state tax increases, and cessation practices. Even after controlling for sociodemographic factors (age, race/ethnicity, income, education, marital status, employment status, and foreign-born status) smoking rates were highest in Central Harlem and in the South Bronx. Sixteen percent of nonsmokers reported frequent exposure to second-hand smoke at home or in a workplace. Among smokers with a child with asthma, only 33% reported having a no-smoking policy in their homes. More than one fifth of smokers reported reducing the number of cigarettes they smoked in response to the state tax increase. Of current smokers who tried to quit, 65% used no cessation aid. These data were used to inform New York City's smoke-free legislation, taxation, public education, and a free nicotine patch give-away program. In conclusion, large, local surveys can provide essential data to effectively advocate for, plan, implement, and evaluate a comprehensive tobacco control program.

Adolescent↗
PubMed2005

A space-time permutation scan statistic for disease outbreak detection.

BACKGROUND: The ability to detect disease outbreaks early is important in order to minimize morbidity and mortality through timely implementation of disease prevention and control measures. Many national, state, and local health departments are launching disease surveillance systems with daily analyses of hospital emergency department visits, ambulance dispatch calls, or pharmacy sales for which population-at-risk information is unavailable or irrelevant. METHODS AND FINDINGS: We propose a prospective space-time permutation scan statistic for the early detection of disease outbreaks that uses only case numbers, with no need for population-at-risk data. It makes minimal assumptions about the time, geographical location, or size of the outbreak, and it adjusts for natural purely spatial and purely temporal variation. The new method was evaluated using daily analyses of hospital emergency department visits in New York City. Four of the five strongest signals were likely local precursors to citywide outbreaks due to rotavirus, norovirus, and influenza. The number of false signals was at most modest. CONCLUSION: If such results hold up over longer study times and in other locations, the space-time permutation scan statistic will be an important tool for local and national health departments that are setting up early disease detection surveillance systems.

Data Interpretation, Statistical↗
PubMed2005

Use of pharmacy data to evaluate smoking regulations' impact on sales of nicotine replacement therapies in New York City.

OBJECTIVES: Recently, New York City and New York State increased cigarette excise taxes and New York City implemented a smoke-free workplace law. To assess the impact of these policies on smoking cessation in New York City, we examined over-the-counter sales of nicotine replacement therapy (NRT) products. METHODS: Pharmacy sales data were collected in real time as part of nontraditional surveillance activities. We used Poisson generalized estimating equations to analyze the effect of smoking-related policies on pharmacy-specific weekly sales of nicotine patches and gum. We assessed effect modification by pharmacy location. RESULTS: We observed increases in NRT product sales during the weeks of the cigarette tax increases and the smoke-free workplace law. Pharmacies in low-income areas generally had larger and more persistent increases in response to tax increases than those in higher-income areas. CONCLUSIONS: Real-time monitoring of existing nontraditional surveillance data, such as pharmacy sales of NRT products, can help assess the effects of public policies on cessation attempts. Cigarette tax increases and smoke-free workplace regulations were associated with increased smoking cessation attempts in New York City, particularly in low-income areas.

Health Promotion↗
PubMed2005

Adult tobacco use levels after intensive tobacco control measures: New York City, 2002-2003.

OBJECTIVES: We sought to determine the impact of comprehensive tobacco control measures in New York City. METHODS: In 2002, New York City implemented a tobacco control strategy of (1) increased cigarette excise taxes; (2) legal action that made virtually all work-places, including bars and restaurants, smoke free; (3) increased cessation services, including a large-scale free nicotine-patch program; (4) education; and (5) evaluation. The health department also began annual surveys on a broad array of health measures, including smoking. RESULTS: From 2002 to 2003, smoking prevalence among New York City adults decreased by 11% (from 21.6% to 19.2%, approximately 140000 fewer smokers). Smoking declined among all age groups, race/ethnicities, and education levels; in both genders; among both US-born and foreign-born persons; and in all 5 boroughs. Increased taxation appeared to account for the largest proportion of the decrease; however, between 2002 and 2003 the proportion of cigarettes purchased outside New York City doubled, reducing the effective price increase by a third. CONCLUSIONS: Concerted local action can sharply reduce smoking prevalence. However, further progress will require national action, particularly to increase cigarette taxes, reduce cigarette tax evasion, expand education and cessation services, and limit tobacco marketing.

Adolescent↗
PubMed2004

The New York City Smoke-Free Air Act: second-hand smoke as a worker health and safety issue.

BACKGROUND: Despite the provisions of a Smoke-Free Air Act (SFAA) enacted in 1995, more than 415,000 non-smoking New York City workers reported exposure to second-hand smoke in the workplace all or most of the time in 2002. Continued exposure to second-hand smoke in New York City prompted a renewed debate about a broader smoke-free air law. METHODS: The approach taken by the New York City Department of Health and Mental Hygiene to make the case for workplace protection from second-hand smoke, counter the opposition's arguments, and ultimately win the support of policymakers and the public for comprehensive smoke-free workplace legislation is described. RESULTS: On December 30, 2002, New York City's Mayor signed the SFAA of 2002 into law, making virtually all workplaces, including restaurants and bars, smoke-free. CONCLUSIONS: Proponents for a stronger law prevailed by defining greater protection from second-hand smoke as a matter of worker health and safety. Efforts to enact smoke-free workplace laws will inevitably encounter strong opposition, with the most common argument being that smoke-free measures will harm businesses. These challenges, however, can be effectively countered and public support for these measures is likely to increase over time by focusing the debate on worker protection from second-hand smoke exposure on the job.

Air Pollution, Indoor↗
PubMed2004

Syndromic surveillance in public health practice, New York City.

The New York City Department of Health and Mental Hygiene has established a syndromic surveillance system that monitors emergency department visits to detect disease outbreaks early. Routinely collected chief complaint information is transmitted electronically to the health department daily and analyzed for temporal and spatial aberrations. Respiratory, fever, diarrhea, and vomiting are the key syndromes analyzed. Statistically significant aberrations or "signals" are investigated to determine their public health importance. In the first year of operation (November 15, 2001, to November 14, 2002), 2.5 million visits were reported from 39 participating emergency departments, covering an estimated 75% of annual visits. Most signals for the respiratory and fever syndromes (64% and 95%, respectively) occurred during periods of peak influenza A and B activity. Eighty-three percent of the signals for diarrhea and 88% of the signals for vomiting occurred during periods of suspected norovirus and rotavirus transmission.

Adolescent↗
PubMed2004

Mass smallpox vaccination and cardiac deaths, New York City, 1947.

In April 1947, during a smallpox outbreak in New York City (NYC), more than 6 million people were vaccinated. To determine whether vaccination increased cardiac death, we reviewed NYC death certificates for comparable periods in 1946, 1947, and 1948 (N = 81,529) and calculated adjusted relative death rates for the postvaccination period. No increases in cardiac deaths were observed.

Adult↗
PubMed2004

Long-term prognosis for clinical West Nile virus infection.

Relatively little is known about the long-term prognosis for patients with clinical West Nile virus (WNV) infection. We conducted a study to describe the recovery of New York City residents infected during the 1999 WNV encephalitis outbreak. Patients were interviewed by telephone on self-perceived health outcomes 6, 12, and 18 months after WNV illness onset. At 12 months, the prevalence of physical, functional, and cognitive symptoms was significantly higher than that at baseline, including muscle weakness, loss of concentration, confusion, and lightheadedness. Only 37% achieved a full recovery by 1 year. Younger age at infection was the only significant predictor of recovery. Efforts aimed at preventing WNV infection should focus on elderly populations who are at increased risk for neurologic manifestations and more likely to experience long-term sequelae of WNV illness. More studies are needed to document the long-term sequelae of this increasingly common infection.

Activities of Daily Living↗
PubMed2003

Implementing syndromic surveillance: a practical guide informed by the early experience.

Syndromic surveillance refers to methods relying on detection of individual and population health indicators that are discernible before confirmed diagnoses are made. In particular, prior to the laboratory confirmation of an infectious disease, ill persons may exhibit behavioral patterns, symptoms, signs, or laboratory findings that can be tracked through a variety of data sources. Syndromic surveillance systems are being developed locally, regionally, and nationally. The efforts have been largely directed at facilitating the early detection of a covert bioterrorist attack, but the technology may also be useful for general public health, clinical medicine, quality improvement, patient safety, and research. This report, authored by developers and methodologists involved in the design and deployment of the first wave of syndromic surveillance systems, is intended to serve as a guide for informaticians, public health managers, and practitioners who are currently planning deployment of such systems in their regions.

Bioterrorism↗
PubMed2003

Use of ambulance dispatch data as an early warning system for communitywide influenzalike illness, New York City.

In 1998, the New York City Department of Health and the Mayor's Office of Emergency Management began monitoring the volume of ambulance dispatch calls as a surveillance tool for biologic terrorism. We adapted statistical techniques designed to measure excess influenza mortality and applied them to outbreak detection using ambulance dispatch data. Since 1999, we have been performing serial daily regressions to determine the alarm threshold for the current day. In this article, we evaluate this approach by simulating a series of 2,200 daily regressions. In the influenza detection implementation of this model, there were 71 (3.2%) alarms at the 99% level. Of these alarms, 64 (90%) occurred shortly before or during a period of peak influenza in each of six influenza seasons. In the bioterrorism detection implementation of this methodology, after accounting for current influenza activity, there were 24 (1.1%) alarms at the 99% level. Two occurred during a large snowstorm, 1 is unexplained, and 21 occurred shortly before or during a period of peak influenza activity in each of six influenza seasons. Our findings suggest that this surveillance system is sensitive to communitywide respiratory outbreaks with relatively few false alarms. More work needs to be done to evaluate the sensitivity of this approach for detecting nonrespiratory illness and more localized outbreaks.

Ambulances↗