Impact of reduced nicotine content on behavioral economic measures of cigarette reinforcement in adolescents who smoke cigarettes.

BACKGROUND: Public health officials in the U.S. and New Zealand are considering a reduced nicotine standard for cigarettes to reduce their addictive potential. This study's aim was to evaluate the effects of nicotine reduction on the reinforcing efficacy of cigarettes in adolescents who smoke, which has implications for this policy's potential for success. METHODS: Adolescents who smoked cigarettes daily (n = 66; mean age: 18.6) participated in a randomized clinical trial assessing effects of assignment to very low nicotine content (VLNC; 0.4 mg/g nicotine) or normal nicotine content (NNC; 15.8 mg/g nicotine) cigarettes. Hypothetical cigarette purchase tasks were completed at baseline and the end of Week 3 and demand curves fit to the data. Linear regressions estimated effects of nicotine content on demand for study cigarettes at baseline and Week 3 and associations between baseline demand for cigarette consumption at Week 3. RESULTS: An extra sum of squares F-test of fitted demand curves indicated that demand (α) was more elastic among VLNC participants at baseline and Week 3 (F(2, 1016)= 35.72, p < 0.001). Adjusted linear regressions indicated demand was more elastic (ß= 1.45, p < 0.01) and maximum expenditure (Omax) lower (ß= -1.42, p-0.03) among VLNC participants at Week 3. More elastic demand for study cigarettes at baseline predicted lower consumption of cigarettes at Week 3 (p's < 0.01). CONCLUSIONS: A nicotine reduction policy may reduce the reinforcing value of combustible cigarettes among adolescents. Future work should investigate likely responses to such a policy among youth with other vulnerabilities and evaluate the potential for substitution to other nicotine containing products.

Associations Between Nicotine Knowledge and Smoking Cessation Behaviors Among US Adults Who Smoke.

INTRODUCTION: Misperceptions about nicotine's contribution to smoking-related health harms could complicate efforts to reduce the public health burden of smoking. Study goals were to describe nicotine knowledge among adults who smoke and investigate whether misperceiving nicotine as a source of health harm was associated with beneficial health behaviors, or lower uptake of using less harmful sources of nicotine to support smoking cessation attempts. METHOD: This study used longitudinal data from 9140 adults who participated in four waves of the Population Assessment of Tobacco and Health Study and were current smokers during the first wave. Logistic regressions estimated odds ratios for correct responses across six aspects of nicotine knowledge assessed in Wave 4. Longitudinal models estimated associations between misperceptions and cigarette consumption, and odds of making a quit attempt; self-reported cessation; e-cigarette use; and use of NRT or e-cigarettes to support quit attempts. RESULTS: Participants who were non-White, older, and had lower educational attainment or income tended to be least knowledgeable about nicotine. Misperceiving nicotine as harmful to health was associated with increased odds of quit attempts (AOR: 1.12, 95% CI: 1.03, 1.23), lower odds of cessation success (AOR: 0.84, 95% CI: 0.73, 0.98) and e-cigarette use (AOR: 0.79, 95% CI: 0.72, 0.86), and lower odds of using NRT (AOR: 0.84, 95% CI: 0.71, 0.99) or e-cigarettes to support quit attempts (AOR: 0.59, 95% CI: 0.49, 0.71). CONCLUSION: Harm reduction efforts may be impeded by misperceptions about nicotine. Further work should evaluate the effects of correcting such misperceptions through public education. IMPLICATIONS: This study provides longitudinal evidence that among adult smokers, misperceiving nicotine as a primary cause of smoking-related diseases may be associated with reduced cessation success and lower likelihood of using less harmful nicotine products. These misperceptions may therefore impede efforts to encourage smokers ready to quit to use evidence-based cessation support such as nicotine replacement during quit attempts and limit the success of policies designed to shift smokers to less harmful sources of nicotine. Further work should evaluate the longitudinal effects of correcting nicotine misperceptions through public education targeted toward adults who smoke.

Abnormal allometric size of vital body organs among sudden infant death syndrome victims.

Sudden infant death syndrome (SIDS) victims are difficult to describe physically because they seem outwardly indistinguishable in nearly all characteristics from infants (alive or dead) of comparable chronological age. Relative (allometric) size of vital organ and body weights has not been examined among SIDS victims. In the present study, autopsy organ and body weights for 152 SIDS deaths (1-12 months) were compared with the results of 115 controls that were trauma or illness-related death (0.25-12 months). A pattern of abnormal relative size in vital organs (brain, heart, liver, and kidney) was revealed. In allometric regressions, increase in the weights of the organs relative to total body weight among SIDS victims were approximately three times the increase among controls in the first year of life. This finding indicates a disturbance of normal patterns of vital organ size of SIDS victims that is of unknown etiology. Am. J. Hum. Biol. 12:382-387, 2000. Copyright 2000 Wiley-Liss, Inc.

Implementing problem-based learning in a family medicine clerkship.

BACKGROUND AND OBJECTIVES: Problem-based learning (PBL) has been implemented in the curriculum of many medical schools, but limited information is available about the outcome of this learning technique. The educational intervention presented in this paper implemented a PBL learning component in our third-year family medicine clerkship and measured the outcomes of this curricular change. METHODS: One third of the curricular time devoted to didactic teaching in our family medicine clerkship was replaced with PBL activities. Simulated cases were developed and presented to students who, with the aid of faculty facilitators, studied the cases, gathered information about the cases, and developed diagnostic and management plans for the cases. The outcome of the intervention was measured by a) comparing students' scores on the National Board of Medical Examiners (NBME) family medicine clerkship examination to scores achieved by students in the year before PBL was introduced and b) students' evaluations of the relevance and success of PBL in the clerkship curriculum. RESULTS: Students' NBME clerkship examination scores increased from a mean of 66 the year before PBL began to 73 after PBL was implemented. More than 80% of students reported that PBL was a good way to learn family medicine, and 85% reported that the PBL technique provided sufficient information to formulate learning issues. CONCLUSIONS: PBL can be introduced into a third-year family medicine clerkship curriculum with general acceptance by students. Students rated the technique highly, and their examination scores improved.

Verifying the curriculum of a family medicine clerkship.

The learning experience during a medical school clinical rotation is largely shaped by students' patient encounters. This paper reports on how a log system for recording these encounters can be used for course planning and evaluation. Over the past 5 years, 960 third-year students completed log forms based on their clinical encounters during a required 4-week family medicine clerkship at UT Southwestern. These forms were then optically scanned and the information entered into a computerized database. Log form data revealed that the most common medical problems encountered by students in their ambulatory settings were similar to those reported in the general family practice literature. There was a great deal of consistency in the types of encounters from year to year. The data also showed some differences among clerkship sites in terms of patient demographics and the most frequently reported diagnoses. Information generated from student log forms has been used by the clerkship faculty to determine required readings, prioritize didactic topics and other teaching, adjust curriculum content, prepare support materials and develop examinations. Given the utility of the information obtained and the ease of use of optical mark encounter sheets, we recommend this system for other clerkships.

Treatment of acute bronchitis in adults. A national survey of family physicians.

BACKGROUND: The purpose of this study was to determine how family physicians in the United States treat acute bronchitis in an otherwise healthy adult. METHODS: A 33-item questionnaire on the diagnosis and treatment of acute bronchitis was mailed to a random sample of 500 physicians who are members of the American Board of Family Practice. RESULTS: Thirty-two of the 500 sampled physicians could not be located by mail; 265 of those who received the questionnaire responded. The response rate was 57% (265/468). Sixty-three percent of responding physicians indicated that antibiotics are their first choice of treatment for the otherwise healthy, nonsmoking adult with acute bronchitis. The decision to use antibiotics as the first choice of treatment did not vary by physician's sex, age, years in practice, practice location, practice type, or percentage of HMO patients. Only 6% of responding physicians reported using beta 2 agonist bronchodilators as their first choice of treatment. Physicians in this study stated that they prescribe an antibiotic 75% of the time in treating nonsmoking patients with acute bronchitis (first choice or otherwise). If the patient is a smoker, physicians reported that they prescribe antibiotics 90% of the time (F = 110.25; df = 1; P > .0001). Physicians reported that for patients who smoke it takes longer for coughs to totally resolve and longer for them to return to a normal activity level than for nonsmokers. CONCLUSIONS: Family physicians report that antibiotics are their most common treatment for acute bronchitis in the otherwise healthy adult. Previous clinical trials have shown only marginal improvement in symptoms when patients with this condition are treated with an antibiotic. With antibiotic resistance emerging as a major global health problem, it is essential that other methods of treatment be evaluated.

Diagnosis of acute bronchitis in adults: a national survey of family physicians.

BACKGROUND: The purpose of this study was to determine how family physicians in the United States diagnose acute bronchitis in otherwise healthy adults. METHODS: A 33-item questionnaire on the diagnosis and treatment of acute bronchitis was mailed to a random sample of 500 physicians who are members of the American Board of Family Practice. RESULTS: Two hundred sixty-five physicians responded. Of those who did not respond, 32 could not be located. Of those who did respond, 10 were either retired or were practicing in another specialty. The net response rate was 56% (255/458). Responding physicians stated that character of cough and sputum production are the most important items used in diagnosing acute bronchitis. Fifty-eight percent indicated that the cough should be productive, and 60% stated that the sputum should be purulent. Seventy-two percent of respondents did not feel that wheezing or rhonchi need to be present. Younger physicians and those who selected antibiotics as their first treatment choice were more likely to define acute bronchitis as the presence of a productive cough with purulent sputum (P < .05). Physicians from an academic setting were more likely to define acute bronchitis as a productive cough (P < .05). Thirty-six percent of physicians from practices serving populations with > or = 60% managed care patients included wheezing or rhonchi in the definition of acute bronchitis, compared with 26% of all others (P < .05). CONCLUSIONS: Variations in the diagnosis of acute bronchitis in otherwise healthy adults can be attributed to physician age, treatment choice, and practice setting. A significant number of family physicians did not require a productive cough as part of the diagnostic criteria for acute bronchitis. This finding needs to be considered in studies evaluating treatment. Additional qualitative studies are necessary to identify other factors involved in diagnosing acute bronchitis.

Risk of chromosomal abnormalities, with emphasis on live-born offspring of young mothers.

In a large public urban hospital obstetrics service with > 123,000 deliveries in a 10-year period (1980-89), the frequencies (0.12%) of any type of chromosomal abnormality and of trisomy syndromes were analyzed for maternal age-related risk, by logistic regression. Focusing on very young gravidas, we found that in the study period there were 9,332 births (7.5% of all deliveries) to mothers < or = 16 years old. Estimated risks of chromosomal abnormalities among offspring associated with very young maternal age (9-16 years) were similar to those age-associated risks of mothers 20-29 years old. Risks of chromosomal abnormalities increase with advancing maternal age and are independent of ethnicity.

Computerized performance support systems: applications in a family practice clerkship.

This article describes a computerized performance support system, the Clerkship Learning Expert and Resource Consultant (CLERC), developed to improve the quality and consistency of learning available to medical students in a third-year family practice clerkship. CLERC is an integrated computer system with an interactive knowledge base, software applications, literature search capabilities, and clinical diagnostic software programs. Medical students enrolled in a third-year family practice clerkship use CLERC to access up-to-date clinical information and to complete clerkship assignments.

Reliability of birth certificate reporting of congenital anomalies.

Birth certificates comprise an important source of data on the prevalence of genetic conditions and for monitoring possible teratogens in the population. Investigators have found wide variability (12 to 100%) in the accuracy of reporting. In a large public hospital, of those congenital anomalies detected at birth, only 5.4% were recorded on the birth certificate. This is one of the lowest rates ever reported. An underreporting correction factor may be applied if congenital anomalies are distributed randomly with respect to reporting status, and the rate of reporting is sufficient to comprise a valid sample for estimating a correction factor (that is, 20% or more reported). In this study, factors such as numbers or types of anomalies, race, infant birthweight, or estimated gestational age did not significantly influence the rate of birth certificate reporting. Thus, our data satisfied the first but not the second criterion for derivation of a correction factor. In conducting epidemiologic studies, birth certificate data should be used with: (1) great caution; (2) a system of validation with the medical record to estimate the degree of underreporting and to derive a correction factor; and (3) a priori knowledge that underreporting of congenital anomalies on this document is highly prevalent.

Is hyperthermia teratogenic in the human?

Maternal hyperthermia during embryogenesis has been postulated to cause a variety of major congenital anomalies in exposed offspring. Although the literature regarding human exposures is not conclusive, studies using animal models support the contention that major structural anomalies may be produced. In the present study, pregnancy outcome of a cohort of women who reported having a temperature of 101 degrees F or higher for 24 hours or more during the first trimester was compared to a control group of women (matched on last menstrual period, parity, and age) who denied having a fever. A statistically significant increased frequency of a specific type of congenital anomaly, abdominal wall defects, was found in offspring whose mothers had sustained high temperatures during embryogenesis. Although an increased risk of this type of congenital anomaly is not consistent with previous epidemiologic studies, similar defects of this organ system have been reported in offspring of pregnant nonhuman primates (monkeys) and rodents (guinea pigs) who experienced hyperthermia during pregnancy.

Brain growth among fetuses exposed to cocaine in utero: asymmetrical growth retardation.

Fetal growth retardation may be associated with maternal cocaine use during pregnancy. The pattern of fetal growth retardation was analyzed in infants born to 80 women who used cocaine, but not alcohol, during pregnancy, and in two comparison groups: 100 infants born to mothers who used neither alcohol nor cocaine during pregnancy and 67 infants whose mothers used alcohol but not cocaine during pregnancy. There were statistically significant differences in head size between the unexposed and cocaine-exposed infants (P less than .001). Notably, head circumference was reduced proportionately more than birth weight in cocaine-exposed infants, a pattern similar to that observed in alcohol-exposed infants. Alcohol- and cocaine-exposed infants were not statistically different in head circumference. We conclude that brain growth of cocaine-exposed infants is similar to that reported for alcohol-exposed infants, and that cocaine-exposed infants may be characterized as having asymmetrical growth retardation.

HIV prevalence in pregnant intravenous drug users in Dallas, Texas.

Information available regarding the prevalence of human immunodeficiency virus (HIV) in pregnant women indicates that the primary risk factor for infection is intravenous drug use. At Parkland Memorial Hospital in Dallas, Texas, approximately 4.7% of pregnant women reported using intravenous drugs. The estimated prevalence of HIV infection among pregnant intravenous drug users at this hospital was 3.3%. This is similar to the HIV infection rates reported for nonpregnant parenteral drug-using populations in other areas of the southwestern United States, suggesting that there may be a lower rate of endemic infection in this region of the country.

Failure to recognize fetal alcohol syndrome in newborn infants.

A clinically distinct constellation of major and minor anomalies, termed the fetal alcohol syndrome, occurs among infants whose mothers abuse alcohol during pregnancy. In addition, significantly higher rates of pregnancy complications, including perinatal deaths and fetal growth retardation, occur among these women and their offspring. We studied the medical records of 40 infants born to 38 alcohol abusers and the frequency of characteristics associated with fetal alcohol syndrome. Physical examinations of 6 infants revealed primary features consistent with a diagnosis of fetal alcohol syndrome. Postnatal growth and development were very poor in 17 (50%) of 34 liveborn alcohol-exposed infants. The diagnosis of fetal alcohol syndrome did not appear in the medical records of any of these infants despite the fact that the mothers' obstetric records included a history of alcohol abuse during pregnancy. This finding emphasizes the importance of good communication between obstetric and pediatric medical staff at this hospital, particularly when providing care for pregnant women and newborn infants at high risk for complications due to maternal alcohol or other drug abuse.

Effects of T's and blues abuse on pregnancy outcome and infant health status.

T's and blues (pentazocine and tripelennamine) abuse during pregnancy has been reported to be associated with adverse maternal and fetal effects. In this study, conducted at Parkland Memorial Hospital in Dallas, Texas, pregnancy outcome and health status of infants born to 23 T's and blues abusers were compared to a group of 100 unexposed women and their infants. Infants born to T's and blues abusers had significantly reduced birthweight, length, head circumference, and an increased frequency of major congenital anomalies (3 of 23), including two congenital cardiac anomalies. However, one of these cardiac anomalies occurred in the offspring of a woman who also reported moderate to heavy daily alcohol use during pregnancy. The other cardiac anomaly occurred in association with in utero anoxia. We therefore surmise that a known teratogen (alcohol) and perinatal complications caused two of the major anomalies, and not the pentazocine-tripelennamine combination per se.

Patterns of multiple substance abuse during pregnancy: implications for mother and fetus.

This paper describes patterns of drug use such as choice of drug, other substances abused, and route of administration in 174 women who reported methamphetamine, cocaine, heroin, or "Ts and blues" abuse during pregnancy. Seventy-five percent (130/174) reported using more than one drug. Other than tobacco, alcohol and cocaine were the drugs most frequently used in combination with other drugs (7% to 53% and 12% to 54% of the time, respectively). The extent of polydrug use observed in this study emphasizes (1) the difficulty in ascribing adverse maternal or fetal health effects to single substances, and (2) the potential for interaction effects due to multiple substance abuse.

Maternal and fetal effects of heroin addiction during pregnancy.

Heroin addiction during pregnancy has been reported to be associated with adverse maternal and perinatal effects. In a study of a large obstetric service in Dallas, pregnancy outcome and health status of infants born to 24 heroin addicts were compared to those in a group of 100 unexposed women and their infants. Women who used heroin during pregnancy tended to use other substances (tobacco, alcohol, cocaine) more often than did controls. The frequency of preterm birth was increased significantly in women who abused heroin during pregnancy. Sexually transmitted diseases were not increased in frequency in pregnant heroin addicts as compared to women who did not use heroin during pregnancy. Heroin addicts had infants who were significantly shorter and lighter in weight than did controls. No significant differences in head circumference or frequency of congenital anomalies were observed.

Blood lead levels and growth status of children.

Several studies have shown that elevated blood lead (Pb) levels in children are associated with decreased growth. Among 139 children aged 1 to 10 years (66 male, 73 female) who attended a Pb clinic in Dallas, Texas, growth was decreased by 1.6 cm in height, 1.4 kg in weight, and 0.6 cm in head circumference for each 10 µg/dl increase in blood Pb. Consistent with previously reported effects of Pb, several clinical symptoms (hearing deficit, dental problems, hyperactivity) were increased in frequency among children with high blood Pb levels (X̄Pb = 34.6 µg/dl ± 5.6) compared to the children in the low Pb level group (X̄Pb = 11.9 µg/dl ± 3.3). Interestingly, pica was significantly increased in frequency among children in the high Pb group, indicating oral consumption of non-food matter was a major source of Pb intoxication. These results suggest that increased Pb level is an important risk factor for growth deficits in children.

Alcohol abuse during pregnancy: changes in frequency in a large urban hospital.

The reported frequency of alcohol abuse during pregnancy was studied in a large urban public hospital in Dallas, Texas. During 1977-1980, 5602 pregnant women were surveyed and 0.7% (95% confidence interval 0.6-0.8%) reported abusing alcohol during pregnancy. In 1987, 1.4% (95% confidence interval 1.3-1.5%) of 1032 pregnant women, who were surveyed before delivery, reported alcohol abuse according to the same definition used 10 years earlier. The increase in the frequency of reported alcohol abuse during pregnancy between 1977-1980 and 1987 is statistically significant (P less than .05).

Cocaine abuse during pregnancy: maternal and fetal implications.

Cocaine abuse during pregnancy has been reported to be associated with a variety of fetal complications and with preterm labor. In this cohort study, pregnancy outcome and health status of infants born to 53 cocaine abusers were compared with those of another group of 100 unexposed women and their infants. Significantly more (P less than .05) pregnancies of abusers were associated with preterm labor. In addition, significantly more (P less than .05) infants had complications at birth (ie, meconium, tachycardia). Infants born to cocaine abusers also had significantly lower (P less than .05) birth weight than infants of controls, and an excess of congenital cardiac anomalies (P less than .01).