The role of behavioral experience in judging risks.

This study used conditional risk assessments to examine the role of behavioral experiences in risk judgments. Adolescents and young adults (ages 10-30; N = 577) were surveyed on their risk judgments for natural hazards and behavior-linked risks, including their personal experiences with these events. Results indicated that participants who had experienced a natural disaster or engaged in a particular risk behavior estimated their chance of experiencing a negative outcome resulting from that event or behavior as less likely than individuals without such experience. These findings challenge the notion that risk judgments motivate behavior and instead suggest that risk judgments may be reflective of behavioral experiences. The results have implications for health education and risk communication.

Adolescents' and adults' understanding of probability expressions.

PURPOSE: To examine whether there are differences between adolescents and adults in their interpretation of probability terms. METHODS: Participants were 20 fifth graders, 54 seventh graders, 45 ninth graders, and 34 young adults (mean adult age = 26.24 years, standard deviation = 2.09) from the San Francisco Bay area. They completed a self-administered survey asking them to assign percentage estimates (0% to 100%) to 30 randomly ordered probability terms. RESULTS: Significant age differences in the mean percentage estimates for 8 of the 30 terms were shown. Moreover, we found large variation in the interpretation of most probability terms studied, with larger variation among the adolescents than adults. Finally, all age groups had some difficulty correctly differentiating between "possibly" and "probably". CONCLUSIONS: Owing to wide variation in the interpretation of probability terms, both within and across age groups, we suggest health practitioners use percentages rather than probability terms to convey risk to both adolescents and adults.

Preventive services in a health maintenance organization: how well do pediatricians screen and educate adolescent patients?

OBJECTIVE: To determine whether pediatricians in managed care settings adhere to national guidelines concerning the provision of clinical preventive services. DESIGN: Surveys were mailed between September 1996 and April 1997 to all pediatricians practicing in a California group-model health maintenance organization. The survey asked pediatricians about their screening and education practices on 34 recommended services and the actions taken with adolescent patients who have engaged in risk behavior. RESULTS: The response rate was 66.2% (N = 366). Pediatricians, on average, screened 92% of their adolescent patients for immunization status and blood pressure; 85% for school performance; 60% to 80% for obesity, sexual intercourse, cigarette use, alcohol use, drug use, and seat belt and helmet use; 30% to 47% for access to handguns, suicide, eating disorders, depression, and driving after drinking alcohol; fewer than 20% for use of smokeless tobacco, sexual orientation, sexual and physical abuse, and riding a bike or swimming after drinking alcohol; and 26% to 41% for close friends' engagement in risk behavior. Pediatricians' assessment and education with adolescent patients who screened positive for risk behavior was particularly low. Female physicians, physicians who saw a greater proportion of older adolescents, and recent medical school graduates were more likely to provide preventive services. CONCLUSIONS: Pediatricians in this health maintenance organization provide preventive services to adolescent patients at rates below recommendations but at rates greater than physicians in other practice settings. Improvement is especially needed in the areas that contribute most to adolescent mortality and for patients who screen positive for a risk behavior.

Influence of physician confidentiality assurances on adolescents' willingness to disclose information and seek future health care. A randomized controlled trial.

CONTEXT: Adolescents' concerns about privacy in clinical settings decrease their willingness to seek health care for sensitive problems and may inhibit their communication with physicians. OBJECTIVE: To investigate the influence of physicians' assurances of confidentiality on adolescents' willingness to disclose information and seek future health care. DESIGN: Randomized controlled trial. SETTING: Three suburban public high schools in California. PARTICIPANTS: The 562 participating adolescents represented 92% of students in mandatory classes. INTERVENTION: After random assignment to 1 of 3 groups, the adolescents listened to a standardized audiotape depiction of an office visit during which they heard a physician who assured unconditional confidentiality, a physician who assured conditional confidentiality, or a physician who did not mention confidentiality. MAIN OUTCOME MEASURES: Adolescents' willingness to disclose general information, willingness to disclose information about sensitive topics, intended honesty, and likelihood of return visits to the physician depicted in the scenario were assessed by anonymous written questionnaire. RESULTS: Assurances of confidentiality increased the number of adolescents willing to disclose sensitive information about sexuality, substance use, and mental health from 39% (68/175) to 46.5% (178/383) (beta=.10, P=.02) and increased the number willing to seek future health care from 53% (93/175) to 67% (259/386) (beta=.17, P<.001). When comparing the unconditional with the conditional groups, assurances of unconditional confidentiality increased the number of adolescents willing to return for a future visit by 10 percentage points, from 62% (122/196) to 72% (137/190) (beta=.14, P=.001). CONCLUSIONS: Adolescents are more willing to communicate with and seek health care from physicians who assure confidentiality. Further investigation is needed to identify a confidentiality assurance statement that explains the legal and ethical limitations of confidentiality without decreasing adolescents' likelihood of seeking future health care for routine and nonreportable sensitive health concerns.

Relationship of alcohol use and risky sexual behavior: a review and analysis of findings.

In this review article, three methodologic approaches that have been used to examine the association between adolescents' alcohol use and their involvement in risky sex are discussed: global correlation studies, situational covariation studies, and event analyses. The strengths and limitations of each of these research methods are discussed. An extensive review of the most rigorous studies, which used event analysis to examine the alcohol-risky sex link, reveals positive results for first-time sexual events but equivocal findings for other types of sexual relationships. It is argued that differences in the types of sexual relationships studied have been confounded, limiting our ability to evaluate the extent to which alcohol has a causal influence on adolescents' condom use. It is suggested that future investigations consider the nature of the sexual relationship, and go beyond studying the length or status of the relationship to explore how variation in relationship dimensions such as trust and intimacy affect adolescents' sexual behavior.

PIP: Research on the association between alcohol use and high-risk sexual practices among US adolescents has been compromised by methodological flaws. Global correlation studies, situational covariate studies, and event-history analyses have examined the impact of alcohol on adolescents' condom use. Although the correlation studies have found an association between alcohol consumption and risky sexual behavior, they can not identify potential causal effects. Situational covariate studies have examined effects from the use of alcohol during sexual events, but they also obscure the important temporal relationship between variables. Both global correlation and situational covariation studies fail to address the possibility that alcohol use and risky sexual behavior are caused by a third factor such as a general tolerance for deviance or a predisposition to risk taking. Critical incident or event analyses are limited by the recall bias inherent in retrospective data. Support for an alcohol-risky sex association emerges most consistently from studies that examined first-time sexual intercourse events, but this finding may not generalize to later experiences with new partners. Recent studies have recognized the importance of examining how sexual relationships themselves influence condom use. It is possible that alcohol will affect condom use only at specific points in the relationship. To control for the potentially confounding effects of the partner relationship on the alcohol-risky sex link, the natural history of these behaviors over the course of a relationship should be examined. The use of diaries is likely to yield more reliable information than retrospective questioning.

Language preference and communication development of a hearing and deaf twin pair.

This observational study examined the development and use of communication in a pair of deaf and hearing monozygotic twins from 13 months of age until 36 months of age. One twin contracted meningitis at 7 months, leaving her profoundly deaf but without other measurable sequelae. The other twin is normal in all respects. The prelingual twins were enrolled in a total communication preschool program where, with their parents, they participated in activities designed to enhance the language skills of deaf children. The twins were videotaped monthly, first at their preschool program and later at home. All forms of communication were recorded, including signs, vocalizations, and hand and body gestures. Additionally, eye gaze direction and body positions during communication were noted. Comparisons between the deaf and hearing twins showed that although both children were able to learn language and communicate successfully, the hearing twin preferred a vocal form of language, whereas the deaf twin used mostly sign language. Moreover, the hearing twin's communication was usually responsive, while the deaf twin's communication was comprised mostly of imitative signs and gestures. Methods of teaching a profoundly deaf child to communicate are discussed.

Biochemical and hematologic correlates of alcoholism and liver disease.

Quadratic multiple discriminant analysis of 25 commonly ordered laboratory tests resulted in correct classification of 100% of nonalcoholics without overt liver disease, 98% of alcoholism treatment program patients with presumed mild liver involvement, 96% of alcoholics with liver disease, and 89% of nonalcoholics with liver disease. Direct comparison of the biopsy-verified alcoholic and nonalcoholic liver disease groups resulted in 100% discrimination, and removal of traditionally evaluated liver tests from the battery of 25 tests did not substantially alter the original classification accuracy. Alcoholic and nonalcoholic liver disease was still 100% differentiable when equated for number of patients with cirrhosis, hepatitis, and hepatitis combined with cirrhosis or fibrosis. Additional utility of the quadratic discriminant approach was demonstrated when 83% alcoholic and 83% nonalcoholic liver disease cases were diagnosed correctly in a prospective manner. In contrast, use of aspartate aminotransferase to alanine aminotransferase ratios (ie, SGOT to SGPT) identified correctly 75% and 33% of patients, respectively.

Decreased hepatic uroporphyrinogen decarboxylase activity in porphyria cutanea tarda.

To test whether reduced hepatic uroporphyrinogen decarboxylase activity is a specific and intrinsic defect in porphyria cutanea tarda, we measured enzymatic activity in the livers of 17 patients with porphyria cutanea tarda, 12 "normal" control patients without liver disease, and 41 patients with other forms of porphyria, alcoholic liver disease, hemochromatosis, or chronic hepatitis. Enzyme activity in all the patients with porphyria cutanea tarda was lower than in the patients without this disease, except for one patient with alcohol-induced fatty liver. Reduction of hepatic iron stores by phlebotomy did not alter the enzymatic activity in porphyria cutanea tarda. We conclude that reduced hepatic uroporphyrinogen decarboxylase activity is a specific and intrinsic hepatic defect in porphyria cutanea tarda, but modulation of uroporphyrinogen synthesis by extrinsic factors is required for the full biochemical expression of the disease.

Porphyria cutanea tarda (PCT) in a patient with chronic renal failure on haemodialysis.

Porphyria cutanea tarda, diagnosed by reduced levels of red cell uroporphyrin decarboxylase and raised plasma porphyrins, developed in a patient with chronic renal failure due to polycystic kidneys, treated with haemodialysis, who had normal total faecal porphyrins. Haemodialysis did not alter plasma porphyrin levels and we deduced that most of the plasma porphyrins were circulating in high molecular weight protein complexes.

Chronic persistent hepatitis and unconjugated hyperbilirubinemia.

The authors studied 12 patients with chronic persistent hepatitis and persistent or intermittent mild unconjugated hyperbilirubinemia. Maximum serum total bilirubin concentration ranged from 2.1 to 3.6 mg/dl. Hemolysis was not evident. Hepatic bilirubin UDP-glucuronyltransferase activity assayed in each patient ranged from 0.16 to 0.39 U (mean +/- SEM = 0.27 +/- 0.02) compared to 0.68-1.99 (1.35 +/- 0.08) in 23 normals, 0.78-2.28 (1.41 +/- 0.05) in 53 patients with acute hepatitis, 0.34-1.74 (0.81 +/- 0.09) in 16 patients with anicteric chronic persistent hepatitis, and 0-0.62 (0.24 +/- 0.03) in 33 patients with Gilbert's syndrome. The mean UDP-glucuronyltransferase activity was significantly lower in anicteric chronic persistent hepatitis compared to normals, but higher than in Gilbert's syndrome. The incidence of unconjugated hyperbilirubinemia among first degree relatives was 0:32 in icteric chronic persistent hepatitis compared to 24:85 (28%) in Gilbert's syndrome. These results show that the likely cause for the unconjugated hyperbilirubinemia associated with chronic persistent hepatitis is an acquired depression of hepatic bilirubin UDP-glucuronyltransferase activity. The data suggest that the enzyme defect is related to chronic persistent hepatitis.

Red-cell uroporphyrinogen decarboxylase activity in porphyria cutanea tarda and in other forms of porphyria.

To test the diagnostic specificity of reduced red-cell uroporphyrinogen decarboxylase activity for porphyria cutanea tarda, we measured enzymic activity in 29 normal subjects and 65 patients with various forms of porphyria. Only patients with porphyria cutanea tarda had subnormal enzymic activity. Patients with acute intermittent porphyria, erythropoietic protoporphyria, variegate porphyria and hereditary coproporphyria had normal or slightly elevated activities. The enzymic activity in normal persons and patients with porphyria cutanea tarda did not differ according to sex. Reduction of iron stores did not alter the enzymic activity in porphyria cutanea tarda. We conclude that reduced red-cell uroporphyrinogen decarboxylase activity is a specific and intrinsic defect in porphyria cutanea tarda; measurement of this enzyme is a reliable diagnostic test for this disease.

Posttraumatic epilepsy and acute intermittent porphyria: effects of phenytoin, carbamazepine, and clonazepam.

A patient with uncontrolled posttraumatic epilepsy and acute intermittent prophyria was subjected to successive therapeutic trials with phenytoin, carbamazepine, and clonazepam, while eating an adequate diet. Both phenytoin and carbamazepine treatments caused significant increases in porphobilinogen excretion and appeared to induce acute porphyric attacks. In contrast, treatment with clonazepam under rigid dietary control for 10 days caused no increase in porphilbinogen excretion. During the subsequent 7 months of treatment with clonazepam, neither seizures nor porphyric attacks recurred. These findings suggest that clonazepam may be a safe and effective treatment for chronic or severe generalized seizure disorders in patients with acute intermittent porphyria.

Reduced hepatic bilirubin uridine diphosphate glucuronyl transferase and uridine diphosphate glucose dehydrogenase activity in the human fetus.

Hepatic bilirubin uridine diphosphate glucuronyl transferase (UDPG-T) activity was 0.14 and 0.22 units in two fetuses aged 17 and 22 weeks, respectively, and less than 0.1 unit in 15 fetuses, aged 8--19 weeks compared to 0.68--1.99 units in 21 normal adults. Hepatic uridine diphosphate glucose dehydrogenase (UDPG-D) activity in 14 fetuses, aged 8--18 weeks, ranged from 6.2--15.0 units (mean = 11.3 +/- 0.7) compared to 28.8--49.2 units (mean = 39.6 +/- 2.5) in eight normal adults (P less than 0.001). There was no correlation between UDPG-D activity and gestational age. The hepatic UDPG-D activity was 16.5 units in a 33-day-old full term, female infant, 42.4 and 24.3 units in two 2-year-old infants, respectively, and 24.3 units in a 5.5-year-old child. In three human fetuses, the apparent Km UDPG was 0.54 x 10(-4) M. Thus, both hepatic bilirubin UDPG-T and UDPG-D activity are markedly reduced in the human fetus during the second trimester of gestation. Retarded development of hepatic UDPG-D may extend beyond the first month of life.

Type B hepatitis after needle-stick exposure: prevention with hepatitis B immune globulin. Final report of the Veterans Administration Cooperative Study.

Hepatitis B immune globulin (HBIG) and immune serum globulin (ISG) were examined in a randomized, double-blind trial to assess their relative efficacies in preventing type B hepatitis after needle-stick exposure to hepatitis B surface antigen (HBsAG)-positive donors. Clinical hepatitis developed in 1.4% of HBIG and in 5.9% of ISG recipients (P = 0.016), and seroconversion (anti-HBs) occurred in 5.6% and 20.7% of them respectively (P less than 0.001). Mild and transient side-effects were noted in 3.0% of ISG and in 3.2% of HBIG recipients. Available donor sera were examined for DNA polymerase (DNAP) and e antigen and antibody (HBeAg; anti-HBE). Both DNAP and HBeAg showed a highly statistically significant correlation with the infectivity of HBsAg-positive donors. Hepatitis B immune globulin remained significantly superior to ISG in preventing type B hepatitis even when the analysis was confined to these two high-risk subgroups. The efficacy of ISG in preventing type B hepatitis cannot be ascertained because a true placebo group was not included.

Effect of changes in dietary components on the serum bilirubin in Gilbert's syndrome.

Patients with Gilbert's syndrome were placed on low calorie diets and isocaloric diets sequentially severely reduced in carbohydrate, protein, or fat content. Significant increases in the serum bilirubin concentration occurred after the low calorie diet, but not after the isocaloric nutrient-depleted diets. Thus caloric deprivation per se and not changes in dietary components is responsible for diet-induced hyperbilirubinemia.

Efficacy of hepatitis B immune serum globulin after accidental exposure. Preliminary report of the Veterans Administration Cooperative Study.

A randomised, double-blind, controlled trial has been undertaken to compare the efficacy of hepatitis B immune globulin (H.B.I.G.) with that of immune serum globulin (I.S.G.) for the prophylaxis of viral hepatitis. Participants in the trial were individuals exposed accidentally to material infectious for hepatitis (primarily viral B hepatitis). Preliminary evaluation of the first 302 of the 561 individuals entered into the study indicates that H.B.I.G. significantly reduced the frequencies of both clinical and subclinical hepatitis during the first 3--4 months after the injection. Less than 10% of H.B.I.G. recipients had detectable anti-HBs at the sixth month after the injection, suggesting that H.B.I.G. might need to be given every 3--4 months to continually exposed individuals. Further long-term evaluation is required in order to define more clearly those most likely to benefit from H.B.I.G.

Caloric intake and unconjugated hyperbilirubinemia.

Reduction in caloric intake was associated with a greater absolute rise in the serum bilirubin concentration in patients with Gilbert's syndrome and partial hepatic bilirubin uridine diphosphate glucuronyltransferase (UDPG-T) dysfunction compared to patients with hemolytic unconjugated hyperbilirubinemia and normal subjects. Two patients with overt hemolysis but an exaggerated response to caloric deprivation had reduced UDPG-T activities comparable to Gilbert's syndrome. The UDPG-T activities in the other patients with hemolytic jaundice were normal. The combination of fasting and novobiocin in 2 normal subjects produced a greater increase in bilirubin level than either fasting or novobiocin alone. These data suggest that theunderlying UDPG-T dysfunction, rather than the prefasting level of unconjugated hyperbilirubinemia, is responsible for the diet-induced hyperbilirubinemia in Gilbert's syndrome. The diet test appears to differentiate Gilbert's syndrome from hemolytic jaundice as well as from normal subjects, irrespective of the initial serum bilirubin concentration.