Conducting International Collaborative Research in Developing Nations

International research partnerships bring together some of the best and the brightest in an effort to tackle global health problems. Such collaborations also pose complex challenges, such as maintaining ethical principles in the conduct of research in developing nations. In implementing a randomized clinical trial to reduce postpartum hemorrhage (PPH) during childbirth in rural India, U.S. and Indian collaborators addressed three such issues: the appropriateness of an ethical randomized controlled trial in the developing world, the inclusion of a placebo arm, and the relevance of informed consent in a semiliterate rural population.

Publishing negative findings and the challenge of avoiding type II errors in studies of suspect teratogens: Example of a recent ondansetron publication

It is important that negative, as well as positive, studies be published to complete the available picture in areas of scientific inquiry. At the same time, it is critical that the implications of a negative study not be overstated and generalized when major issues of study design and data accuracy may be the reason that no relationship was discovered. The challenge of avoiding type II errors in interpreting negative findings has major public health implications, especially when the relationship of an exposure to birth defects is the concern. This is particularly important when interpreting the report by Fazio et al. (June issue of Reproductive Toxicology) on the relationship of ondansetron exposure to pregnancy outcome and birth defects. This review addresses the study design and conclusions and suggests that an alternative concluding statement would be more apropos, given the limitations of the data.

Gastric pH and Therapeutic Responses to Exsomeprazole in Patients With Functional Dyspepsia: Potential Clinical Implications

BACKGROUND

Therapy for functional dyspepsia remains a challenge. This study aimed to evaluate esomeprazole (E) versus placebo (P) regarding (1) the effectiveness in providing relief of abdominal pain or discomfort during 16 weeks of therapy in patients with functional dyspepsia having moderate or severe symptoms; (2) the effects on gastric acid suppression and (3) the relationship between symptom relief and gastric pH.

METHODS

Enrolled patients were randomized to E (n = 38) or P (n = 35) in a double-blind, placebo-controlled trial. Outcomes were measured at four 4-week intervals. Drug dose titrated at each visit, based on relief of abdominal symptoms. The 24-hour gastric pH was monitored at baseline, 4 and 8 weeks.

RESULTS

After 4 weeks, 71% of E patients (40mg) reported satisfactory symptom relief versus 34% of P patients (P < 0.001). When the dose for nonresponders (NR) was titrated to 40mg twice daily, the E relief rate increased to 82% versus 56% in P group (P < 0.05). During the next 4 weeks, with dose decreased by half in responders, E response rate declined to 69% versus 48% in P group (P < 0.10). When the dose was increased for NR during the last 4 weeks, E rate increased to 83% versus 57% in P group (P < 0.05). At 4 and 8 weeks for E responders and NR, patients׳ pH >4 value increased significantly compared to baseline.

CONCLUSIONS

(1) Though E 40mg once daily is superior to P, some patients benefit from 40mg twice daily; (2) E, 40mg once daily, profoundly inhibits gastric acid secretion; (3) intragastric pH monitoring before and after therapy may help address the relationship between symptomatic relief and gastric acid secretion and (4) some patients respond to monitored titrated placebo therapy.

Stimulation of Mucin, Mucus, and Viscosity during Lubiprostone in Patients with Chronic Constipation may Potentially Lead to Increase of Lubrication

Objectives:

The purpose of this clinical trial was to explore whether lubiprostone increases the rate of mucus and mucin secretion and its viscosity in chronic constipation (CC) patients. The secretion of chloride (CS) into the gastrointestinal tract lumen is pivotal in the body's ability to process non-digestible food components. CS sets the optimal rate of hydration for non-digestible food components, their fluidity, and their adequate propulsion along the alimentary tract. Chloride is also instrumental in the secretion of alimentary tract mucus, and the formation of a gel-like, viscous mucus-buffer layer. This layer acts as the first line and vanguard of the mucosal barrier. This barrier is essential in mucosal lubrication and protection. Lubiprostone, a novel chloride channel stimulator ClC-2, is currently approved for the treatment of CC. Its impact on mucus, mucus secretion, and viscosity is not established.

Methods:

A double-blind, crossover trial was approved by the IRBs at the Kansas University Medical Center (Kansas City, KS) (study site) and at the Texas Tech University HSC (El Paso, TX) (analysis site). The study included 20 patients (17 females (F); mean age: 37 years) with symptoms of CC diagnosed according to the Rome III criteria. Patients were randomized to 1 week of therapy with lubiprostone or placebo followed by a 1 week washout and 1 week of the alternative therapy. Gastric juice was collected basally and during stimulation with pentagastrin (6 μg/kg body weight subcutaneously) at the end of weeks 1 and 3. Pentagastrin stimulation mimics food stimulation. The mucus content in gastric juice was assessed gravimetrically. The mucin content was measured after its purification using ultracentrifugation. The viscosity of the gastric secretion was measured using a digital viscometer.

Results:

In comparison with placebo, the volume of gastric secretion in patients with CC during administration of lubiprostone increased significantly by 50% (86.3 vs. 57.5 ml/h) (P<0.001) in basal conditions and increased by 25% (210.0 vs. 167.6 ml/h) (P=0.024) during stimulation with pentagastrin. The rate of gastric mucus secretion during therapy with lubiprostone was 91% higher (257.3 vs. 135 mg/h) (P=0.001) in basal conditions and 28% higher (348.1 vs. 270.8 mg/h) (NS) in stimulated conditions, although the latter was not statistically significant. The rate of gastric mucin secretion during lubiprostone therapy was 85% higher (98.4 vs. 65.5 mg/h) (P=0.011) in basal conditions and 38% (98.3 vs. 71.7 mg/h) (NS) higher in stimulated conditions. In basal conditions, the viscosity of gastric secretion during administration of lubiprostone increased by 240% at the lowest (P<0.001) and by 106% at the highest shear rate (P<0.001). In stimulated conditions, it increased by 226% (P<0.01) at the lowest shear rate and by 67% (P<0.01) at the highest shear rate.

Conclusions:

The significantly higher content of gastric mucus and mucin during therapy in basal conditions with lubiprostone in patients with CC suggests and supports the potentially leading role of lubiprostone and ClC-2 stimulation in their secretion. This increased stimulation results in profoundly increased viscosity, which in turn facilitates and/or accelerates the transit and evacuation of non-digestible food components. Although increases in mucus and mucin were observed in stimulated conditions, neither increase was statistically significant. Based on this experiment, we hypothesize that, in CC patients, the significantly increased rate of mucus and its major component, mucin secretion, during lubiprostone administration may partially explain its clinical effectiveness and also have additional clinically important effects. We propose that since the increased mucus production enhances the protective quality of the mucosal barrier, it also boosts its potential to withstand luminal aggressive components such as acid/pepsin duet, Helicobacter pylori and/or nonsteroidal anti-inflammatory drugs/aspirin, or a combination of all. Further trials are needed to test this hypothesis. As this was crossover clinical trial, the patients serve as their own controls. No interaction was found with body mass index (BMI) and treatment. The observed relationships of BMI and mucus and mucin secretions and gastric juice volume are important considerations in the design of future trials, particularly if a crossover design is not used.

Consanguinity, prematurity, birth weight and pregnancy loss: a prospective cohort study at four primary health center areas of Karnataka, India

OBJECTIVE

To determine whether consanguinity adversely influences pregnancy outcome in South India, where consanguinity is a common means of family property retention.

STUDY DESIGN

Data were collected from a prospective cohort of 647 consenting women, consecutively registered for antenatal care between 14 and 18 weeks gestation, in Belgaum district, Karnataka in 2005. Three-generation pedigree charts were drawn for consanguineous participants. χ (2)-Test and Student's t-test were used to assess categorical and continuous data, respectively, using SPSS version 14. Multivariate logistic regression adjusted for confounding variables.

RESULT

Overall, 24.1% of 601 women with singleton births and outcome data were consanguineous. Demographic characteristics between study groups were similar. Non-consanguineous couples had fewer stillbirths (2.6 vs 6.9% P=0.017; adjusted P=0.050), miscarriages (1.8 vs 4.1%, P=0.097; adjusted P=0.052) and lower incidence of birth weight <2500 g (21.8 vs 29.5%, P=0.071, adjusted P=0.044). Gestation <37 weeks was 6.2% in both the groups. Adjusted for consanguinity and other potential confounders, age <20 years was protective of stillbirth (P=0.01), pregnancy loss (P=0.023) and preterm birth (P=0.013), whereas smoking (P=0.015) and poverty (P=0.003) were associated with higher rates of low birth weight.

CONCLUSION

Consanguinity significantly increases pregnancy loss and birth weight <2500 g.

Side effects of oral misoprostol for the prevention of postpartum hemorrhage: results of a community-based randomised controlled trial in rural India

OBJECTIVE

To investigate the side effects of 600 microg oral misoprostol given for the mother and the newborn to prevent postpartum hemorrhage (PPH).

METHODS

One thousand six hundred twenty women delivering at home or subcentres in rural India were randomised to receive misoprostol or placebo in the third stage of labour. Women were evaluated for shivering, fever, nausea, vomiting and diarrhea at 2 and 24 h postpartum. Newborns were evaluated within 24 h for diarrhea, vomiting and fever. Symptoms were graded as absent, mild-to-moderate or severe.

RESULTS

Women who received misoprostol had a significantly greater incidence of shivering (52%vs. 17%, p < 0.001) and fever (4.2%vs. 1.1%, p < 0.001) at 2 h postpartum compared with women who received placebo. At 24 h, women in the misoprostol group experienced significantly more shivering (4.6%vs. 1.4%, p < 0.001) and fever (1.4%vs. 0.4%, p < 0.03). There were no differences in nausea, vomiting or diarrhea between the two groups. There were no differences in the incidence of vomiting, diarrhea or fever for newborns.

CONCLUSIONS

Misoprostol is associated with a significant increase in postpartum maternal shivering and fever with no side effects for the newborn. Given its proven efficacy for the prevention of PPH, the benefits of misoprostol are greater than the associated risks.

Significant enhancement of esophageal pre-epithelial defense by tegaserod: implications for an esophagoprotective effect

BACKGROUND & AIMS

Tegaserod, a serotonin 5-hydroxytryptamine (5-HT)4 receptor agonist, is thought to stimulate intestinal secretions. The aim of the current study was to assess the effect of tegaserod vs placebo on salivary and esophageal protective factors in patients with gastroesophageal reflux disease (GERD).

METHODS

This study was a randomized, double-blind, placebo-controlled, cross-over trial in 38 GERD patients treated with tegaserod 6 mg twice a day vs placebo. Salivary samples were collected basally and during mastication. In addition, in 32 GERD patients, salivary and esophageal secretions also were collected during infusion of NaCl, HCl/pepsin, and NaCl in a consecutive fashion using a specially designed esophageal catheter. Saliva and esophageal perfusates were assessed for the pH, volume, content of buffers, protein, mucin, epidermal growth factor (EGF), transforming growth factor alpha (TGFalpha), and prostaglandin E (PGE)2 and analyzed statistically.

RESULTS

Salivary flow rates during administration of tegaserod increased over corresponding values during both basal conditions (P < .01) and mastication (P < .001). The rate of secretion of salivary bicarbonate and nonbicarbonate buffers also increased in basal conditions (P < .001 and P < .01, respectively) and during mastication (P < .05 and P = .05). Salivary EGF increased during mastication (P < .05), whereas PGE2 and TGF alpha increased in basal conditions (P < .05 and P < .01). Esophageal perfusate volumes increased during administration of tegaserod in basal conditions (P < .05), whereas esophageal EGF secretion increased after mucosal exposure to HCl/pepsin and subsequent final perfusion with NaCl (P < .05).

CONCLUSIONS

Significant stimulatory impact of 5-HT4 agonist on several salivary protective factors as well as esophageal EGF secretion may have esophagoprotective implications in patients with GERD and may help to address new therapies in the future.

Oral misoprostol in preventing postpartum haemorrhage in resource-poor communities: a randomised controlled trial

BACKGROUND

Postpartum haemorrhage is a major cause of maternal mortality in the developing world. Although effective methods for prevention and treatment of such haemorrhage exist--such as the uterotonic drug oxytocin--most are not feasible in resource-poor settings where many births occur at home. We aimed to investigate whether oral misoprostol, a potential alternative to oxytocin, could prevent postpartum haemorrhage in a community home-birth setting.

METHODS

In a placebo-controlled trial undertaken between September, 2002, and December, 2005, 1620 women in rural India were randomised to receive oral misoprostol (n=812) or placebo (n=808) after delivery. 25 auxiliary nurse midwives undertook the deliveries, administered the study drug, and measured blood loss. The primary outcome was the incidence of acute postpartum haemorrhage (defined as > or =500 mL bleeding) within 2 h of delivery. Analysis was by intention-to-treat. The trial was registered with the US clinical trials database (http://www. clinicaltrials.gov) as number NCT00097123.

FINDINGS

Oral misoprostol was associated with a significant reduction in the rate of acute postpartum haemorrhage (12.0% to 6.4%, p<0.0001; relative risk 0.53 [95% CI 0.39-0.74]) and acute severe postpartum haemorrhage (1.2% to 0.2%, p<0.0001; 0.20 [0.04-0.91]. One case of postpartum haemorrhage was prevented for every 18 women treated. Misoprostol was also associated with a decrease in mean postpartum blood loss (262.3 mL to 214.3 mL, p<0.0001). Postpartum haemorrhage rates fell over time in both groups but remained significantly higher in the placebo group. Women taking misoprostol had a higher rate of transitory symptoms of chills and fever than the control.

INTERPRETATION

Oral misoprostol was associated with significant decreases in the rate of acute postpartum haemorrhage and mean blood loss. The drug's low cost, ease of administration, stability, and a positive safety profile make it a good option in resource-poor settings.

Drape estimation vs. visual assessment for estimating postpartum hemorrhage

OBJECTIVE

To compare (1) visual estimation of postpartum blood loss with estimation using a specifically designed blood collection drape and (2) the drape estimate with a measurement of blood loss by photospectrometry.

METHODS

A randomized controlled study was performed with 123 women delivered at the District Hospital, Belgaum, India. The women were randomized to visual or drape estimation of blood loss. A subsample of 10 drape estimates was compared with photospectrometry results.

RESULTS

The visual estimate of blood loss was 33% less than the drape estimate. The interclass correlation of the drape estimate to photospectrometry measurement was 0.92.

CONCLUSION

Drape estimation of blood loss is more accurate than visual estimation and may have particular utility in the developing world. Prompt detection of postpartum hemorrhage may reduce maternal morbidity and mortality in low-resource settings.

The impact of a school entry law on adolescent immunization rates

PURPOSE

Middle school entry laws increase coverage with recommended vaccines, but their effect on vaccines that are not required is unknown. We compared vaccination coverage for hepatitis B, tetanus and diphtheria (Td), and measles, mumps and rubella (MMR) in areas of states with discordant middle school, hepatitis B school entry laws, and evaluated the relationship between demographic characteristics and adolescent immunization rates.

METHODS

Retrospective design with purposive school sampling, using location of residence to determine study group. In each school, immunization records from a random sample of up to 75 students in ninth grade (affected by a new hepatitis B law) and 12th grade (not affected by the law) from 11 schools in two areas discordant for the law were analyzed. All areas had long standing two-dose MMR and Td requirements.

RESULTS

Ninth graders in schools with the law had hepatitis B rates higher (72.8%) than those without the law (18.6%) (U = 2.0, p < .01). There were no significant differences between grades or schools for MMR and Td. However, even in the presence of the law, rates were significantly lower in schools with lower socioeconomic indicators.

CONCLUSIONS

Middle school immunization laws are effective at raising adolescent hepatitis B, but in this study there wasn't enough power to discern the effect on rates for other vaccines or the influence of demographic variables on rates. Results suggested that laws did not appear to completely overcome disparities. For school mandates to be more effective, additional efforts, presumably on enforcement, especially in areas with lower socioeconomic indicators, are needed.

Initiating a novel therapy in preventing postpartum hemorrhage in rural India: a joint collaboration between the United States and India

BACKGROUND

Maternal mortality rates in India are estimated at 560/100,000 live births and postpartum hemorrhage (PPH) accounts for 35-56% of these deaths. Given that 50% of births in rural India occur at home, oral Misoprostol administered by minimally trained midwives may be an effective uterotonic agent for preventing PPH when the use of other uterotonics is not feasible. While the import for testing the effectiveness of this intervention may be readily obvious, the elements essential for the conduct of a scientific study in rural areas served by indigenous health workers may not be as evident.

METHODS

We present the design as well as the preparation and development of an ongoing NICHD sponsored U.S.-Indian collaborative randomized, placebo-controlled, clinical trial (RCT) conducted in four Primary Health Center areas of Belgaum District, Karnataka, India. The primary goal of the trial is to assess the effectiveness of Misoprostol 600 microg orally in reducing the incidence of acute PPH (> or = 500 mL) in women delivering at home or in neighboring sub-centers. 1600 pregnant women will be randomized to receive Misoprostol or placebo immediately post-delivery of the infant. However, beyond testing the scientific merit of the RCT, this study also tests the feasibility of having indigenous midwives regularly using Misoprostol in rural areas as well as the willingness of these communities to accept this intervention. In addition, this paper also explores the international and community collaborations necessary for the conduct of this study.

FINDINGS

It is necessary to have several critical elements in place, including international collaboration between the Indian and US research sites, funding through a private/public collaboration and trained scientists, as well as commitment from the community for the successful conduct of such a study. In the development and implementation of a RCT, careful attention must be paid to the training of field personnel involved in the delivery process and developing a data collection and monitoring system to ensure that information gathered is valid.

CONCLUSIONS

A joint U.S.-Indian collaboration to test the efficacy and the feasibility of an innovative method to reduce PPH can serve as collaborative model to develop additional interventions to improve maternal mortality and morbidity. If Misoprostol is shown to be sufficiently safe and efficacious in the prevention of PPH, the appropriate government agencies will be encouraged to make the drug available to midwives (ANMs) and rurally located physicians for whom parenteral medications are either not permitted or impractical and/or unavailable. Such a project can serve as a model applicable to rural settings throughout the developing world for improving delivery practices and reducing maternal mortality and morbidity. These are important public health concerns in India and other developing nations.

Secular trends in Q wave and non-Q wave acute myocardial infarction. The Minnesota Heart Survey

The Minnesota Heart Survey examined trends of Q wave and non-Q wave acute myocardial infarction (AMI) using a 50% random sample of all hospital discharges of patients with AMI or another acute coronary disease from 35 of 36 hospitals in 1970 and 30 of 31 hospitals in 1980 in the Minneapolis-St. Paul metropolitan area. A total of 1,901 and 1,864 potential AMI cases were abstracted in 1970 and 1980, respectively. Electrocardiograms were coded according to the Minnesota code. AMIs were validated by computerized algorithm based on chest pain, enzymes, electrocardiograms, and autopsy. This study shows that with the use of a consistent, standard diagnostic algorithm, attack rates for Q wave AMI did not change significantly between 1970 and 1980 and that attack rates for non-Q wave AMI decreased significantly during the same decade. However, when the more sensitive cardiac enzymes creatine phosphokinase and creatine phosphokinase-MB were considered, attack rates of both Q wave and non-Q wave AMIs increased. This research documents four important trends for community AMI rates that are at variance with those reported by others. There was a decline in non-Q wave AMI attack rates from 1970 to 1980; women had outcomes equal to or worse than those for men for both case-fatality and 7-year survival rates; patients with non-Q wave AMIs had worse in-hospital prognoses than those with Q wave AMIs; and 7-year survival rates were worse for Q wave AMI in 1980. These findings demonstrate the need for standard diagnostic criteria for Q wave and non-Q wave AMI if trends are to be monitored. In the future, as new trials of operative and nonoperative therapies of AMI are undertaken, these considerations will increase in importance.

The effect of the number of electrocardiograms analyzed on cardiovascular disease surveillance: the Minnesota Heart Survey (MHS)

One method used to control costs in community cardiovascular disease surveillance is to limit the number of electrocardiograms (ECGs) used to validate acute myocardial infarction (AMI). The Minnesota Heart Survey investigated the impact of decreasing the maximum number of ECGs analyzed on classification of ECG pattern and final AMI diagnosis (definite, probable, none). A 50% sample of all 1980 acute CHD hospital discharge records (ICD-9 code 410 or 411) from 30 of 31 Twin Cities hospitals were abstracted. Comparing results using all available ECGs in the record (maximum of 12) with those obtained using up to 4 ECGs showed little differences in the ECG classification or final AMI diagnosis.

The effects of diagnostic criteria on trends in coronary heart disease morbidity: the Minnesota Heart Survey

The Minnesota Heart Survey assessed attack rates of MI in Twin Cities residents ages 30-74 years in 1970 and 1980. The age-adjusted attack rate per 100,000 of definite MI was similar in 1970 (174.2) and 1980 (179.9) p greater than 0.05, using ECG, chest pain, and blood enzyme concentrations of aspartate transaminase and/or lactic dehydrogenase as criteria. The attack rate of definite MI also remained constant when autopsy findings were included in the algorithm, 197.0 in 1970 and 191.4 in 1980 (p greater than 0.05). Adding creatine phosphokinase (CPK) and CPK-MB isoenzyme to the algorithm increased the rate of definite MIs from 209.0 in 1970 to 277.0 in 1980 (p less than 0.001). Interpretation of long-term trends in coronary heart disease morbidity is highly dependent upon variables used to validate cases. Care must be taken to maintain consistent criteria to avoid bias due to improvements in diagnostic techniques over time which increase sensitivity for detection of cardiac ischemia.

Prevalence of cardiovascular disease risk factors in blacks and whites: the Minnesota Heart Survey

Two cross-sectional surveys were conducted in 1985 and 1986 to measure the prevalence of coronary heart disease (CHD) risk factors in Blacks and Whites. A home interview was followed by a survey center visit. Participation rates were 78 per cent and 90 per cent for the home interview and 65 per cent and 68 per cent for the survey center visit. Adjusted for age and education, systolic and diastolic blood pressure was 3 to 4 mmHg higher in Blacks. Hypertension was more prevalent in Blacks than Whites (44 per cent vs 28 per cent); serum total cholesterol was approximately 0.4 mmol/l lower in Black than White men and 0.08 mmol/l lower in Black than White women. Among men, more Blacks than Whites were current cigarette smokers (44 per cent vs 30 per cent); however, White smokers smoked more cigarettes per day (26 vs 17). Similar differences were noted for women, although the prevalence and quantity of cigarette consumption was less than men. The excess prevalence of these CHD risk factors in Blacks, especially among women, may explain their elevated CHD and stroke mortality rates in the Twin Cities.

Use of aspirin for prevention of cardiovascular disease--1981-82 to 1985-86: the Minnesota Heart Survey

The efficacy of aspirin to prevent ischemic cardiovascular disease has received considerable attention recently. To determine the prevalence of aspirin use for cardiovascular disease prevention, the Minnesota Heart Survey examined population-based samples of Twin Cities' adults in 1981 to 82 and 1985 to 86. Over the 4-year period, reported use of aspirin for cardiovascular disease prophylaxis increased from 0.6% to 2.4% in women (p less than 0.05) and from 1.7% to 3.3% in men (p = 0.10). Prophylactic aspirin use was more common in older than in younger adults, in whites than in blacks, in those with a history of cardiovascular disease or hypercholesterolemia, and in health professionals and nonsmokers. Some individuals were apparently taking aspirin for "primary" prevention, although it has not yet been approved for that reason. Use of aspirin for cardiovascular disease prevention has been increasing and is likely to increase more rapidly over the next few years. This could favorably impact on mortality rates of cardiovascular disease, but untoward side effects of aspirin may be expected to increase as well.

Comparability of mortality follow-up before and after the National Death Index

Prior to 1979, epidemiologic studies which included mortality follow-up on large cohorts relied on death certificates from last state of residence and expensive follow-up techniques to determine survival. Beginning with 1979, the National Death Index can be used to search death certificate files from all 50 states, the Virgin Islands, and Puerto Rico. This paper addresses the issue of whether mortality follow-up in epidemiologic studies based on a single state death certificate search using only data available in 1970-1975 can be compared with post-1979 mortality follow-up using the National Death Index. This question was addressed by following a cohort of 2,925 coronary heart disease and cerebrovascular disease 1980 hospital discharges from 1980 through 1983 with the use of both the National Death Index and the Minnesota Death Index (MINNDEX). Algorithms for evaluating potential death certificate matches were developed independently for both systems. The systems agreed on the survival status of 98% of the cohort, and both identified 31% as dead. This study supports the comparison of results of National Death Index follow-up to pre-National Death Index studies using algorithms such as the MINNDEX, and provides evidence that trend analyses relying on single state death searches pre-1979 and on the National Death Index from 1979 are valid, particularly in chronically ill persons.

Prevalence of coronary heart disease risk factors in an urban black population: the Minnesota Heart Survey, 1985

A cross-sectional study of a sample of Minnesota black urban residents was conducted in 1985 to develop cardiovascular risk profiles. Participants were evaluated during a home interview (N = 1,254, 78% participation) and a survey center visit (N = 1,052, 65% participation). Black men had significantly higher mean systolic and diastolic blood pressure than Black women (129.7/80.9 vs 124.8/77.3, respectively). Age-specific values for systolic and diastolic blood pressure were greater in men than women for all age categories. Men were more likely to have uncontrolled hypertension or to be unaware of their hypertension than women in all age categories. Women had significantly higher mean total and high-density lipoprotein cholesterol values than men (202.1 and 56.1 mg/dl vs 193.2 and 48.7 mg/dl, respectively). Age-specific values for total and high-density lipoprotein cholesterol values were greater in women than men for all age categories except the 35-44 age group. Men were significantly more likely to be current cigarette smokers (43.3% vs 33.2%) and to have higher cigarette consumption per day (17 vs 14) than women. The major risk factors for cardiovascular disease (with the exception of smoking) were lower in the Minnesota study in 1985 than in the National Health and Nutrition Examination Survey in 1976-1980. These lower levels may also be a component in the decline of cardiovascular disease mortality rates among Blacks.

Postmarketing surveillance methodologies

This article describes and discusses the strengths and limitations of the major pharmacoepidemologic methodologies employed in postmarketing drug surveillance and describes the current status of the U.S. surveillance system. The main methodologies employed in postmarketing drug surveillance include controlled clinical trials, observational epidemiologic studies (cohort, case-control, cross-sectional), demographic methods, drug utilization surveys, spontaneous reports, and automated databases linking medications and disease. Examples of pharmacoepidemiologic studies using each of these methodologies are presented. When a question arises about the efficacy and/or safety of a marketed drug, typically a mixture of these study methodologies is employed. The article concludes with a brief discussion of the role of the Food and Drug Administration, pharmaceutical manufactures, and academic institutions in initiating and conducting postmarketing drug studies.

Trends in cardiovascular risk factors in an urban black population, 1973-74 to 1985: the Minnesota Heart Survey

Cardiovascular disease mortality rates have fallen dramatically in blacks in the United States. To determine whether this may be due to a decline in cardiovascular risk factors, we compared risk factors in a 1985 urban black population, ages 35 to 69, with those obtained in blacks of the same area in 1973-74. Age-adjusted mean body mass and the prevalence of overweight increased significantly over the 12-year period in both men and women. Mean systolic blood pressures declined significantly in both sexes, diastolic blood pressure declined significantly in men, and the proportion of men and women hypertensives on medication and under control increased. The overall prevalence of cigarette smoking changed very little, but the proportion of heavy smokers decreased significantly in men. No significant changes occurred in resting heart rate. Concurrently with these risk factor trends, age-adjusted heart disease mortality rates in area blacks fell 27% between 1968-73 and 1979-84, and stroke mortality fell 58%. Changing risk factors may be contributing to declining cardiovascular mortality rates in blacks. However, overweight seems to be a worsening problem.

Improvement in long-term survival among patients hospitalized with acute myocardial infarction, 1970 to 1980. The Minnesota Heart Survey

The mortality rate associated with coronary heart disease in the United States has declined steadily since 1968, but the reasons for this favorable trend have not been completely elucidated. In particular, it is not clear to what extent the decline reflects decreasing incidence as opposed to improved survival. To assess whether improved survival after myocardial infarction has contributed to the decline, the Minnesota Heart Survey compared the four-year survival rate in patients discharged with a diagnosis of acute myocardial infarction from hospitals in the Twin Cities area in 1970 and 1980. After adjustment for clinical characteristics related to outcome, the survival rate among patients with a definite myocardial infarction was significantly higher in the 1980 than in the 1970 group. The four-year survival for men was 35 percent better in the 1980 than in the 1970 group (95 percent confidence interval, 21 to 50 percent), and for women it was 27 percent better (95 percent confidence interval, 1 to 46 percent). Improvement in survival during the period of hospitalization accounted for 70 percent of the overall gain in survival between 1970 and 1980 in men and for virtually all of the gain in women. We conclude that improved long-term survival among patients with acute myocardial infarction has made an important contribution to the decline in mortality from coronary disease.

A potential use of the National Death Index for postmarketing drug surveillance

A particularly difficult problem for both the Food and Drug Administration and the pharmaceutical manufacturer is evaluation of the importance of spontaneous reports of suspected drug-associated fatalities. These reports are rare, and usually no accurate denominator data on drug use exist. This article proposes that the National Death Index be used to calculate mortality rates for selected drugs as part of the postmarketing surveillance efforts of the government and manufacturers. When hypotheses are generated from spontaneous reports and/or the mortality data, additional studies can be conducted on the cohorts that were identified for mortality follow-up.

Clinical evaluation of methods of treatment

Veterinary clinicians can make a significant contribution to the knowledge of the practical value of using alternative treatment methods by conducting clinical trials. By following a logical sequence of steps the clinician can design and participate in a clinical trial in his clinic without interfering with his normal practice. The successive stages of a field trial were presented along with an example to demonstrate the application of the principles involved. These stages are: design and planning, implementation, collection of data, and analysis of data.The veterinary clinician who initiates clinical trials to answer questions plaguing him provides two services to the veterinary profession. First, he helps answer questions facing private practitioners throughout the profession. Second, he can demonstrate that not all research must be done in a laboratory setting isolated from "real world" complications. Seeing the results that can be derived from individual practicing veterinarians participating in clinical trials should act as a stimulus to other veterinarians to logically organize the data coming from their practices.