Design and statistical analysis of oral medicine studies: common pitfalls

A growing number of articles are emerging in the medical and statistics literature that describe epidemiologic and statistical flaws of research studies. Many examples of these deficiencies are encountered in the oral, craniofacial, and dental literature. However, only a handful of methodologic articles have been published in the oral literature warning investigators of potential errors that may arise early in the study and that can irreparably bias the final results. In this study, we briefly review some of the most common pitfalls that our team of epidemiologists and statisticians has identified during the review of submitted or published manuscripts and research grant applications. We use practical examples from the oral medicine and dental literature to illustrate potential shortcomings in the design and analysis of research studies, and how these deficiencies may affect the results and their interpretation. A good study design is essential, because errors in the analysis can be corrected if the design was sound, but flaws in study design can lead to data that are not salvageable. We recommend consultation with an epidemiologist or a statistician during the planning phase of a research study to optimize study efficiency, minimize potential sources of bias, and document the analytic plan.

Driver's license and voter registration lists as population-based sampling frames for rural African Americans

PURPOSE

To compare coverage of a state driver's license list and county voter registration lists as frames for sampling rural African Americans.

METHODS

Name, birth date, sex, and county were extracted from records for all 18--59 year-old African Americans residing in eight rural North Carolina counties and listed in the North Carolina Driver license file [obtained as a SAS dataset from the University of North Carolina (UNC) Highway Safety Research Center] and in machine-readable text files of registered voters (obtained from county boards of elections). Files were edited, merged, and matched by last name and date of birth to produce three files for each five-year age group, sex, and county: 1) persons listed only in the driver's file; 2) persons listed only in the voter's file; and 3) persons listed in both.

RESULTS

The median percentages of unique persons found only on the driver's list, only on the voter's list, and on both lists were 54%, 17%, and 30% men, and 35%, 25%, and 41% women, respectively.

CONCLUSIONS

The driver's list provided better coverage than did voter registration lists. Federal legislation that prohibits states from releasing driver's license lists for use in surveys removes a valuable resource for population-based research.

Firearm storage practices of officers in a law enforcement agency in the South

BACKGROUND

Law enforcement officers play an important role in promoting firearm safety. This study examined their firearm-related attitudes and practices.

METHODS

We conducted an anonymous, self-administered survey of law enforcement officers in an agency in the South concerning firearm ownership, storage practices, and opinions.

RESULTS

The 207 respondents (response rate=71%) were primarily white (60%) and male (89%). The proportions of respondents with (55%) and without (45%) children were similar. Eighty percent of the officers had firearms in addition to the one they were issued for work. Most stored firearms unlocked (59%) and loaded (68%); almost half (44%) reported storing firearms both unlocked and loaded. Eighty-five percent indicated that they felt an added need to protect themselves and family because of their job. Those who reported having firearms for self-protection were less likely than those who had firearms for recreation to store firearms securely. As compared to those without children, law enforcement officers with children were more likely to store firearms safely, and were especially likely to store firearms locked up (chi(2)=12.72, p<0.0001). Respondents favored background checks, mandatory safety training, and enforcement of storage laws. Three quarters approved of government safety regulations for handguns.

CONCLUSIONS

Despite the law enforcement officers' prominent role in firearm safety promotion and support for initiatives that limit unauthorized access, our study found that many do not practice safe storage. Apparently, many officers keep their firearms stored unlocked and loaded for the purpose of protecting themselves and their families. Addressing concerns about personal safety is a necessary step in promoting safe storage to law enforcement officers.

"Love our kids, lock your guns": a community-based firearm safety counseling and gun lock distribution program

BACKGROUND

Safer storage practices may reduce injury rates by limiting youth access to firearms.

OBJECTIVE

To determine if a firearm safety counseling and gun lock distribution program improved storage practices.

DESIGN

Community-based before-after trial.

SETTING

Urban county in central North Carolina.

PARTICIPANTS

One hundred twelve adult gun owners recruited through a mass media advertising campaign.

INTERVENTION

In the parking lot of a shopping mall, participants completed a survey, and were then provided with tailored counseling, gun safety information, a gun lock, and instructions to use it.

MAIN OUTCOME MEASURES

Firearm storage practices, assessed by survey and personal interview (baseline) and telephone interview (6-month follow-up).

RESULTS

Most participants were white (62%), men (63%), had children (58%), and owned a gun for protection (74%). At follow-up, of the 82 participants, 63 (77%) (up from 39 [48%]) reported storing their gun(s) in a locked compartment (P =.004), 59 (72%) (up from 0) reported using gun locks (P =.001), 61 (74%) (up from 57 [69%]) reported storing their ammunition locked in a separate location, 59 (72%) (up from 52 [63%]) reported storing their gun(s) unloaded, and 6 (7%) (down from 15 [18%]) reported storing firearms unlocked and loaded. Participants with children were more likely at baseline to store weapons unlocked and loaded (38 [59%] vs 19 [41%]; P =.02) but were more likely after counseling to lock their weapons (29 [58%] vs 14 [44%]) and remove guns from the home (5 [10%] vs 0 [0%]).

CONCLUSIONS

This program prompted reporting of safer firearm storage practices, particularly among parents. Longer follow-up, verification of self-reports and correct use, testing of gun locks, and monitoring firearm injury rates after distribution programs are needed to establish the public health potential of this approach.

Risk assessment for gonococcal and chlamydial infections in young children undergoing evaluation for sexual abuse

OBJECTIVE

Testing for gonorrhea (GC) and chlamydial (Ct) infection in children who are being evaluated for sexual abuse is invasive and costly. We developed selective criteria to limit unnecessary testing for these infections.

METHODS

Over a 10-year period (May 1988 to May 1998), clinical information was collected in a prospectively designed database for all children ages 0 to 12 years by the WakeMed Child Sexual Abuse Team in Raleigh, North Carolina. The study population comprised 3040 (2414 girls and 626 boys) of the 3064 children evaluated for sexual abuse. Children were interviewed, examined, and tested by culture for GC and Ct orally, rectally, and genitally. Information from referral sources, accompanying guardians, and previous recent physical examinations was recorded. Bivariate analyses and logistic regression were used to develop 2 sets of screening criteria to predict children at greatest risk of infection with: 1) GC and/or Ct (GC/Ct) and 2) GC alone.

RESULTS

Fifty-eight children were identified with GC/Ct infections (37 with GC, 25 with Ct; 4 children were coinfected). The proposed algorithm for GC/Ct infections would have identified all children with these infections, while avoiding testing 56% of children without infection. Using genital cultures only, the proposed risk score for GC/Ct infections would have identified 100% of GC/Ct cases with 85% fewer cultures compared with testing all children with oral, rectal, and genital cultures.

CONCLUSION

The use of a risk assessment algorithm for GC and Ct infections may reduce the cost and trauma of testing young children who are being evaluated for sexual abuse. sexual abuse, gonorrhea, Neisseria gonorrhoeae, chlamydia, Chlamydia trachomatis, sexually transmitted diseases, children.

Social context of sexual relationships among rural African Americans

BACKGROUND

Reasons for the strikingly increased rates of HIV and other sexually transmitted infections (STIs) among African Americans in the rural Southeastern United States remain unclear. Investigators have devoted little attention to the potential influence of the social and economic context on sexual behaviors.

GOAL

To examine the potential influence of these contextual factors on behaviors that promote the transmission of STIs.

STUDY DESIGN

Focus group interviews in which African Americans from rural North Carolina discussed life in their communities and contextual factors affecting sexual behavior.

RESULTS

Respondents reported pervasive economic and racial oppression, lack of community recreation, boredom, and resultant substance abuse. Many perceived a shortage of black men because of their higher mortality and incarceration rates compared with whites, and believed this male shortage to be partly responsible for the concurrent sexual partnerships that they perceived as widespread among unmarried persons.

CONCLUSION

Contextual features including racism, discrimination, limited employment opportunity, and resultant economic and social inequity may promote sexual patterns that transmit STIs.

Frequent re-infection in a community with hyperendemic gonorrhoea and chlamydia: appropriate clinical actions

In a cohort of 1200 individuals experiencing an index infection of gonorrhoea or chlamydia in a rural North Carolina county, we studied the risk factors for re-infection within 16 months. The occurrence of asymptomatic re-infection was estimated from a sample of controls. Re-infection with either of the two STDs occurred in one-quarter (24%) of the study participants and 22% of the controls. The factors associated with re-infection were age less than 25 years, African-American race, male sex, and infection prior to the index infection. The behavioural and attitudinal variables tested were not associated with re-infection. The patterns of re-infection in this study do not provide guidance for targeting resources toward a subgroup of the clinic population. Structuring clinical services to make them more available and acceptable to all potential clinic clients can contribute to decreasing the duration of infections. Lowering the community prevalence in this way will then decrease the likelihood of re-infection rates.

The potential and limitations of data from population-based state cancer registries

Cancer incidence varies markedly among states because of population heterogeneity regarding risk, genetic, and demographic factors. Population-based cancer registries are essential to monitoring cancer trends and control. The Centers for Disease Control and Prevention and the North American Association of Central Cancer Registries, through the National Program of Cancer Registries, are helping state registries generate more and better data nationwide. The National Program of Cancer Registries has supported the enhancement of 36 registries and the creation of 13 new registries in 45 states, 3 territories, and the District of Columbia, providing national standards for completeness, timeliness, and quality; financial support; and technical assistance. Users must be aware of diverse issues that influence collection and interpretation of cancer registry data, such as multiple cancer diagnoses, duplicate reports, reporting delays, misclassification of race/ethnicity, and pitfalls in estimations of cancer incidence rates. Attention to these issues and intense use of the available data for cancer surveillance will enable maximum societal benefit from the emerging network of population-based state cancer registries.

The African-American church: a potential forum for adolescent comprehensive sexuality education

PURPOSE

To investigate the attitudes and beliefs of clergy from African-American churches towards sexuality education and the provision of sexuality education in their churches.

METHODS

A pilot study was designed to survey a convenience sample of clergy leaders from African-American churches about their young adolescent members. The survey asked about priority health topics, prevalence of sexual and drug risk behavior and the clergy's desire for health education programs. The churches were located in a county (1990 population approximately 200,000, 40% African-American) in the southeastern United States.

RESULTS

The respondents' highest priority issues were drugs, violence, HIV/AIDS, pregnancy and alcohol. Many (76%) had discussed one or more of these issues in church. All respondents wanted additional health seminars for their adolescents, though some clergy (30%) excluded some sexual topics (i.e., anal sex, bisexuality, homosexuality, masturbation, oral sex). Only 6% would make condoms available in their churches, but all would allow contraceptive education.

CONCLUSIONS

Many African-American churches are open to including sexuality education among their health education offerings for young adolescents. The church should be considered as a potential forum for providing comprehensive sexuality education for African-American adolescents.

Factors contributing to the poorer survival of black Americans diagnosed with oral cancer (United States)

OBJECTIVE

The purpose of this study was to identify factors that contribute to the poorer survival of blacks in the United States diagnosed with oral cancer.

METHODS

Data for 6,338 whites and 1,165 blacks diagnosed from 1988 to 1993 with squamous cell carcinoma of the oral cavity and pharynx were obtained from the National Cancer Institute's Surveillance, Epidemiology and End Results (SEER) program 1973-1993 Public-Use Database. The covariables were sex, age, geographic area, marital status, socioeconomic status (five census-tract measures), stage, anatomic site, grade, lymph node involvement, tumor size, and treatment. Hazard ratios were estimated with Cox regression.

RESULTS

Adjusted for age and geographic area, the hazard of death from oral cancer was 1.7 (95% confidence interval: 1.5-1.9) times greater among blacks than whites. The addition of the socioeconomic status (SES) variables to the model reduced the hazard ratio for race to 1.3 (1.0-1.7). Further adjustment by stage and treatment reduced the hazard ratio for race to 1.1 (0.9-1.4). In a model containing all covariables (except lymph node involvement and tumor size), the hazard ratio for race remained 1.1 (0.9-1.4). Analyses with the outcome death from any cause gave similar results.

CONCLUSIONS

Lower SES, more advanced stage, and differences in treatment accounted for 86% of the excess hazard of death from oral cancer among blacks.

Trends in human immunodeficiency virus (HIV) counseling, testing, and antiretroviral treatment of HIV-infected women and perinatal transmission in North Carolina

Since 1993, trends in perinatal human immunodeficiency virus (HIV) transmission have been monitored by use of chart review of patients identified at a central diagnostic laboratory. In the population studied, either pre- or postnatal antiretroviral therapy to the infant increased from 21% in 1993 to 95% in 1997. Concurrently, the number of HIV-infected infants declined from 25 in 1993 to 4 in 1997. The complete Pediatric AIDS Clinical Trials Group Protocol 076 regimen was the most effective in reducing transmission (3.1%). Twenty-two of 35 infants who became infected in 1995-1997 had mothers who did not receive antiretroviral therapy, although counseling practices improved with time. In 1995, 87% of the mothers of HIV-seropositive infants were counseled, whereas in 1997, 96% were counseled (P<.005). None of 59 infants tested had high-level phenotypic zidovudine resistance, although 5 (8.8%) of 57 infants had virus isolates with at least one mutation in the reverse transcriptase gene associated with reduced phenotypic susceptibility to zidovudine.

The epidemiology of adolescent homicide in North Carolina from 1990 to 1995

BACKGROUND

Rates of homicides by adolescents under age 18 years tripled from 1984 to 1994. Most studies report data on urban adolescents and young adults as a single age group (age 15-24 years), but homicide characteristics among adolescents, especially those younger than 15 years, may differ from those of young adults.

OBJECTIVE

To describe the homicide characteristics among adolescents age 11 to 18 years in North Carolina from 1990 to 1995.

METHODS

A retrospective, descriptive analysis of adolescent homicides using the medical examiner database. Police interviews provided additional information for cases from 1993 to 1995.

RESULTS

There were 419 victims from 1990 to 1995 (average annual rate: 9.7 per 100000 adolescents; 9.9 in urban counties, 7.1 in rural). Victims were mostly ages 15 to 18 years (85%), male (79%), and black (76%); 48% lagged behind in school, and, by police report, 40% had a criminal record. Only 23% of the identified perpetrators were strangers. Firearms (59% were handguns) were used in 83% of homicides. Proportionally more younger adolescents (age 11-14 years) were killed by means other than firearms than 15- to 18-year-olds (chi2 = 24.2, P = .007). Drug-related motives (23%) were most common, followed by non-drug-related altercations (20%) and retaliations (17%).

CONCLUSIONS

Proportionally more North Carolina adolescents than urban young adults (ages 15-24 years) were killed by firearms (83% vs. 75%). Proportionally fewer adolescents were killed by police, strangers, or intimate partners. Interventions should include reducing access to firearms and drugs, and helping adolescents develop nonviolent strategies to resolve disputes. Efforts should be focused on adolescents who lag behind in school and have criminal records.

Recruitment of minority students to U.S. epidemiology degree programs. The American College of Epidemiology Committee on Minority Affairs

PURPOSE

African-, Hispanic-, and Native Americans are underrepresented in the field of epidemiology including degree programs. As part of the assessment component of its mandate, the American College of Epidemiology Committee on Minority Affairs conducted a survey of minority recruitment activities of U.S. epidemiology degree programs.

METHODS

The survey, containing questions related to marketing activities, institution infrastructure, financial support, academic offerings, and receptive/supportive environment, was mailed to all programs identified in Episource as offering epidemiology degrees. Separate responses were requested concerning activities at the department and school levels.

RESULTS

Fifty-two completed questionnaires were received (response rate of 79%). All but two institutions had at least one activity conducted by either the department or the school. However, all activities were more common at the school- than at the department-level. Indeed, some activities [a written minority student recruitment plan (6% of departments and 52% of schools), personnel with minority recruitment responsibilities (4% of departments and 73% of schools)] were almost exclusively school-sponsored. Although marketing-type activities were the most common minority recruitment tool used by departments, only 21% made visits to minority schools, 17% visited other colleges specifically to recruit minorities, and 12% produced materials targeted to ethnic/racial minorities. Six percent of the departments and 19% of the schools offered financial support (grants, fellowships, scholarships) to almost all underrepresented minority students.

CONCLUSIONS

Even though individual epidemiology degree programs may not see a need for general recruitment activities in order to maintain the size of their applicant pool, minority-specific recruitment activities should be undertaken to enhance and diversify that pool. We recommend that epidemiology departments develop, adopt, and implement comprehensive written plans for the recruitment of underrepresented minority students into their programs.

Perinatal HIV infection and the effect of zidovudine therapy on transmission in rural and urban counties

OBJECTIVES

To assess health care providers' identification of human immunodeficiency virus (HIV)-exposed infants, to ascertain the prevalence of transplacental or oral zidovudine treatment among infants exposed to HIV, and to estimate the impact of zidovudine use on perinatal transmission in rural and urban North Carolina.

DESIGN

Survey of North Carolina newborns tested for HIV infection in 1993 and 1994 compared with the number of anonymous HIV-positive childbearing women.

SETTING

North Carolina hospitals, public health clinics, and private physicians' offices.

MAIN OUTCOME MEASURES

Rates of identification of HIV-exposed infants and of perinatal HIV-1 transmission, determined by HIV culture and polymerase chain reaction testing in the infants.

RESULTS

The proportion of HIV-exposed children in North Carolina who were identified and tested increased from 60% in 1993 to 82% for all of 1994, and to more than 90% for the last quarter of 1994. The HIV-exposed infants born in rural counties were more likely to be recognized than those born in urban counties (P<.001). In 1994, most infants were evaluated relatively early in life: 39% by 1 week of age, 63% by 6 weeks, and 76% by 3 months. Among infants with recognized HIV exposure, transmission decreased significantly between 1993 and 1994, from 21% to 8.5%, respectively (P=.009). After the announcement of the results of the AIDS Clinical Trials Group Protocol 076, zidovudine was given to 75% of HIV-positive women who delivered infants in North Carolina. Only 5.7% of infants who received any zidovudine became infected, compared with 18.9% of infants who received no zidovudine (P=.007).

CONCLUSIONS

Health care providers in North Carolina are identifying most of the state's HIV-seropositive pregnant women, treating them with zidovudine, and testing their infants soon after birth for HIV infection. The use of zidovudine in pregnant women and their infants has reduced perinatal HIV transmission in the state.

Rural gonorrhea in the southeastern United States: a neglected epidemic?

Some rural counties in the southeastern United States are experiencing high rates of gonorrhea; however, existing knowledge of epidemiologic patterns of gonorrhea within communities is from urban areas. This paper describes the epidemiology of gonorrhea within a rural county of North Carolina and compares it with the patterns described for large cities. Data include gonorrhea reports from private physicians and the county health department from August 11, 1992, to August 10, 1993, and ethnographic interviews. The rate among males (1,602 cases per 100,000 person-years) was twice that among females. The risk of reinfection within 6 months of an initial infection (12.9%) was high compared with risks in urban settings. Although case numbers did not cluster by geographical area as described for some cities, case rates did. Factors favoring transmission in rural communities include greater poverty and fewer health care resources than in urban settings, the exchange of sex for crack cocaine, and a lack of anonymity that may cause some people to avoid seeking treatment or acknowledging risky sexual behaviors in a clinical setting. Addressing high rural rates will entail improving access to care, taking extra measures to ensure confidentiality, and dispelling the myth that high rates are limited to cities.

Recruiting minorities into the profession of epidemiology. Surveying the applicants' mail. American College of Epidemiology Committee on Minority Affairs

The underrepresentation in epidemiology of members of racial/ethnic minority groups is greater than in medicine and health fields in general. Using printed recruitment materials, we evaluated the impression that epidemiology programs might make on prospective minority students. Mainstream recruitment materials were solicited from all identifiable U.S. epidemiology programs (n = 70) by requesting copies of typical mailings to prospective students. Of 51 respondents, 46 sent materials that could be analyzed by tabulating and evaluating minority-related content in text and pictures. Materials reflected a generally low-key approach to epidemiology student recruitment. Most minority-related text referred to affirmative action or financial aid and was at the school level rather than specific to the epidemiology programs. Few minority-related epidemiology course titles or research interests were identified. We recommend including more information about epidemiology and its relevance to minority health in mainstream recruitment materials as one possible strategy for increasing the number of minority applicants.

Syphilis in the South: rural rates surpass urban rates in North Carolina

We studied primary and secondary syphilis rates in North Carolina for 1985 through 1993 to elucidate demographic trends and the role of rurality in the state's high rates. Each of the state's 100 counties was classified by rural-urban character; and county-level rates, adjusted for gender, race, and age group, were compared. Syphilis rates rose dramatically during the 9-year period, with most of the increase occurring among women, non-Whites, and rural counties. The rural rates recently surpassed urban rates, with the greatest increase experienced by non-White rural women. The exchange of sex for drugs and characteristics of rural poverty may be fueling these trends.

Racial and ethnic distribution of faculty, students, and fellows in US epidemiology degree programs, 1992. Committee on Minority Affairs of the American College of Epidemiology

The American College of Epidemiology Committee on Minority Affairs assessed the racial/ethnic distribution of faculty, students, and postdoctoral fellows in epidemiology degree programs in the United States in 1992. Fifty-six programs in schools of public health, medicine, or veterinary medicine completed a one-page anonymous questionnaire (85% response rate). Of 711 faculty members (median of 8 per program), 46 (6%) were minorities (US black, Hispanic, or Asian/Pacific Islander). Of 2142 students (1206 masters, 862 doctoral, 74 postdoctoral: median of 17 per program), 293 (14% of all students; 17% of US citizen students) were minorities. In the 46 doctoral programs, there were 36 black students (in 20 doctoral programs), 15 Hispanic students (in 9 programs), and no Native Americans. There were three minority postdoctoral fellows, all blacks (4% of all postdoctoral fellows). Determined, consistent, and sustained efforts will be required to boost the representation of blacks, Hispanics, and Native Americans in epidemiology.

Hepatitis C virus seroprevalence in clients of sexually transmitted disease clinics in North Carolina

BACKGROUND AND OBJECTIVES

The major routes of transmission for hepatitis C virus (HCV) appear to be blood transfusion and injecting drug use (IDU). There is still some controversy concerning the role of sexual transmission in HCV infection.

GOAL OF THIS STUDY

To use a well characterized, high-risk population of STD clinic patients to investigate the role of sexual transmission of HCV and to determine any association between HCV, HBV, and HIV.

STUDY DESIGN

We tested stored sera obtained anonymously from clients attending three STD clinics in North Carolina in 1988 for antibodies to HCV and hepatitis B virus (HBV). An anonymous, self-administered client questionnaire provided patient history and demographic information.

RESULTS

The most important risk factor for either HCV or HBV seropositivity was IDU. The only risk factor associated with HCV seropositivity after the removal of IDUs was age older than 30 years. In contrast, risk factors associated with HBV seropositivity after the removal of IDUs included male gender, age older than 30 years, HIV seropositivity, homosexuality/bisexuality, syphilis seropositivity, and a history of syphilis.

CONCLUSION

Our study of STD clients confirms the important role that IDU plays in infection with HCV, but suggests that sexual transmission plays only a minor role in HCV epidemiology.

A longitudinal analysis of predictors of quitting smoking among participants in a self-help intervention trial

Predictors of 7-day abstinence from smoking were identified among participants in a randomized self-help smoking-cessation intervention trial conducted from 1985 to 1988 in Seattle, WA. Subjects were adult smokers belonging to a health maintenance organization who responded to an offer of free quitting assistance. Self-reported smoking status was assessed at 8, 16, and 24 months following enrollment. Predictors of abstinence were identified by longitudinal data analysis using Generalized Estimating Equations (GEEs), a modeling approach which handles repeated-measures data and accommodates time-dependent as well as time-independent covariates. Seventeen items emerged as significant (p < .05) predictors, with odds ratios ranging from 1.3 to 2.1. While much of the previous work in smoking-cessation research has focused on demographic and smoking history variables, results of this study indicate that emphasis should also be placed on psychosocial/motivational factors and quitting activities as important predictors of abstinence. Longitudinal data analysis represents a powerful technique for handling correlated (repeated measures) data, which may prove very useful for future studies of smoking cessation as well as other dynamic processes.

HIV seroprevalence in sexually transmitted disease clients in a low-prevalence southern state. Evidence of endemic sexual transmission

We studied human immunodeficiency virus (HIV) seroprevalence and risk factors in 3052 clients attending three large public, sexually transmitted disease (STD) clinics in central North Carolina in mid-1988. Anonymous self-administered questionnaires linked to HIV serologies obtained by testing extra blood from syphilis serologies without personal identifiers showed the following characteristics of the respondents: 60% were men, 81% were black, the median age was 24 years, 5% were injecting drug users since 1978, 7% reported a history of syphilis, and 8% of men were homosexual or bisexual. HIV seropositivity was found in 76 subjects (2.5%), including 46% of the homosexual men, 25% of the bisexual men, 1.6% of the heterosexual men, and 0.6% of the women. Elevated HIV seroprevalence rates were found in subjects with a history of or seroreactivity for syphilis (HIV-positive rate of 53% in homosexual or bisexual men, 9% in heterosexual men, 3% in women) and with histories of gonorrhea (HIV-positive rate of 37% in homosexual or bisexual men, 2.6% in heterosexual men, 1% in women), and intercourse (41% in homosexual or bisexual men, 2% in women), prostitute contact (5% in heterosexual men), and sex with casual partners (2% in women). Even a state with a low incidence of acquired immunodeficiency syndrome can include subpopulations with a high HIV seroprevalence, apparently disseminated endemically in association with bacterial STDs.

Results of a randomized trial of partner notification in cases of HIV infection in North Carolina

BACKGROUND

We sought to compare two methods of notifying sex partners of subjects infected with the human immunodeficiency virus (HIV) or persons who had shared needles with them (needle-sharing partners): "patient referral," in which the responsibility for notifying partners was left to the patient, and "provider referral," in which providers attempted to notify partners.

METHODS

Names of sex partners and needle-sharing partners and information on how to locate them were obtained from consenting HIV-infected subjects identified in the HIV-testing programs at three public health departments in North Carolina. The subjects were randomly assigned to a patient-referral group (in which patients had the initial responsibility for notifying their partners) or a provider-referral group (in which the study counselor notified the partners). The success of attempts to notify partners was monitored by means of interviews with counselors conducted both in the field and at the health department.

RESULTS

Of 534 HIV-positive persons identified at the health departments, 247 (46 percent) did not return for counseling after the test, 8 were counseled outside the study, and 117 (22 percent) were ineligible. Of the 162 invited to participate, 88 (54 percent) declined and 74 (46 percent) agreed. The subjects were mostly male (69 percent), black (87 percent), homosexual or bisexual (76 percent of the men), and had a median age of 30 years. Thirty-nine were assigned to the provider-referral group and 35 to the patient-referral group. In the provider-referral group 78 of 157 partners (50 percent) were successfully notified, whereas in the patient-referral group only 10 of 153 (7 percent) were notified. Of the partners notified by the counselors, 94 percent were not aware that they had been exposed to HIV. Overall, 23 percent of the partners notified and tested were HIV-positive.

CONCLUSIONS

In this trial, leaving the notification of partners up to the subjects (patient referral) was quite ineffective, despite the North Carolina law requiring that partners be notified. Partner notification by public health counselors (provider referral) was significantly more effective. Although the effectiveness of notification procedures is constrained by the accuracy of the information provided by HIV-infected patients, counselors who notify the partners of an infected patient can refer them to educational, medical, and support services targeted to persons at high risk for HIV infection and may encourage the adoption of less risky behavior.

Self-help quit smoking interventions: effects of self-help materials, social support instructions, and telephone counseling

Smokers requesting self-help materials for smoking cessation (N = 2,021) were randomized to receive (a) an experimental self-quitting guide emphasizing nicotine fading and other nonaversive behavioral strategies, (b) the same self-quitting guide with a support guide for the quitter's family and friends, (c) self-quitting and support guides along with four brief counselor calls, or (d) a control guide providing motivational and quit tips and referral to locally available guides and programs. Subjects were predominantly moderate to heavy smokers with a history of multiple previous quit attempts and treatments. Control subjects achieved quit rates similar to those of smokers using the experimental quitting guide, with fewer behavioral prequitting strategies and more outside treatments. Social support guides had no effect on perceived support for quitting or on 8- and 16-month quit rates. Telephone counseling increased adherence to the quitting protocol and quit rates.

Demographic and health characteristics of participants and nonparticipants in a work site health-promotion program

Work site health-promotion programs represent an increasingly common attempt by industry to improve the health of employees. The potential impact of programs is limited by nonparticipation, especially among demographic subgroups and those who could most benefit from health behavior change. The present study prospectively examined the relationship of personnel data and self-reported health habits and health status to participation in the health-promotion program at a research and development work site. Thirty-four percent of the 505 employees enrolled in the health-promotion program. White employees were 2.47 times as likely to participate as nonwhites (95% confidence interval, 1.59, 3.83). Those with health maintenance organization health insurance were 1.43 times as likely to participate as were employees with fee-for-service insurance (1.11, 1.84). There was no difference between participants and nonparticipants in self-reported health status, and only slightly more positive health habits were noted among participants. Seatbelt use was 1.65 times more common among participants (1.10, 2.49). The study results are reassuring that such programs do not enroll only the very healthy or those with healthy habits. However, the diminished enrollment of nonwhite employees supports concern that health-related programs may not equally reach all segments of the work force.

Psychosocial predictors of participation in a work site health-promotion program

An understanding of psychosocial factors associated with participation in health promotion programs could lead to targetted interventions to increase enrollment. This study used questionnaires to measure employees' perception of program efficacy, health attitudes, beliefs, social support, and stress prior to the introduction of a comprehensive health promotion program at a research and development work site. The association of these factors with enrollment in the program was then prospectively determined. In addition, open-ended questionnaires were used retrospectively to determine additional factors associated with participation. Of the above factors, only program efficacy was significantly associated with participation in the entire sample. Perceived social support was associated with participation among non-white employees. In open-ended questionnaires, a desire for health information, a desire for help with behavior change, and concern about health status were the most commonly given reasons for participating. The study findings imply that environmental factors operating during the enrollment period at the work site may be more powerful than preexisting attitudes and beliefs in determining participation.

Self-help quit smoking interventions: Effects of self-help materials, social support instructions, and telephone counseling

Smokers requesting self-help materials for smoking cessation (N = 2,021) were randomized to receive (a) an experimental self-quitting guide emphasizing nicotine fading and other nonaversive behavioral strategies, (b) the same self-quitting guide with a support guide for the quitter's family and friends, (c) self-quitting and support guides along with four brief counselor calls, or (d) a control guide providing motivational and quit tips and referral to locally available guides and programs. Subjects were predominantly moderate to heavy smokers with a history of multiple previous quit attempts and treatments. Control subjects achieved quit rates similar to those of smokers using the experimental quitting guide, with fewer behavioral prequitting strategies and more outside treatments. Social support guides had no effect on perceived support for quitting or on 8- and 16-month quit rates. Telephone counseling increased adherence to the quitting protocol and quit rates.

Interpretive criteria of the Western blot assay for serodiagnosis of human immunodeficiency virus type 1 infection

This project was designed to evaluate different criteria used in the interpretation of the human immunodeficiency virus type 1 (HIV-1) Western blot assay on a group of serum samples blinded to the examiner that were collected from individuals attending three different public health departments in central North Carolina. Each individual also completed an anonymous linked questionnaire regarding sociodemographics and risk factors for blood-borne infections. All of the Western blot assays for human immunodeficiency virus type 1 were interpreted according to the criteria established at the University of North Carolina Hospitals, Chapel Hill, the Centers for Disease Control, Atlanta, Ga, in association with the Association of State, Territorial, and Public Health Laboratory Directors, Iowa City, Iowa, the American Red Cross, Washington, DC, the Consortium for Retrovirus Serology Standardization, Davis, Calif, and the Food and Drug Administration, Washington, DC. The results obtained were grouped as positive, negative, and indeterminate according to each organization's criteria and analyzed in the context of the associated risk factors. The results indicate that institutions performing human immunodeficiency virus type 1 Western blot confirmatory testing should adopt the criteria of the Centers for Disease Control and the State, Territorial, and Public Health Laboratory Directors.

Participation in a smoking cessation program: a population-based perspective

We examined factors associated with participation in an HMO-based, self-help smoking cessation trial by comparing participants with nonparticipating smokers who responded to a prior health survey. Recruitment to the trial was accomplished through the HMO's monthly magazine sent to all enrollee households, and the health survey involved a random sample of the enrollee population. Participants were more likely to be female, older, better educated, and heavier smokers with more attempts to quit in the past. Participants consistently reported poorer levels of health status (self-perceived health and energy, life satisfaction, depression, and symptoms), less healthy lifestyles (exercise and dietary fat), and a greater conviction that smoking cessation would improve how they feel than nonparticipants. These findings confirm previous suggestions that formal cessation programs attract those with a more extensive history of addiction, prior failure, and pathophysiologic effects and may provide clues to increasing motivation among smokers with a greater likelihood of treatment success.

Atypical metaplasia and incidence of bronchogenic carcinoma

The prognostic implication of atypical squamous metaplasia of the respiratory tract has been uncertain, especially for mild atypia. The relation between degree of severity of atypical metaplasia as detected by sputum cytology and incidence of bronchogenic carcinoma was assessed among 14,414 men aged 45 years or older who smoked one or more packs of cigarettes per day. Trial participants underwent sputum cytologic evaluations every 4 months for an average of 7.4 years as part of the Cooperative Early Lung Cancer Detection Program of the National Cancer Institute and were followed for the development of lung cancer between 1971 and 1983 at three institutions: The Johns Hopkins University, the Memorial Sloan-Kettering Cancer Center, and the Mayo Clinic. Analysis with logistic regression controlling for age, race, occupational exposures to lung carcinogens, average number of cytology records per year, and smoking habits revealed that the estimate of the relative rate (RR) of developing bronchogenic carcinoma was greater among men who had mild atypia as compared with men who had negative cytology readings, but there were marked differences among institutions (RR = 1.1, 95% confidence interval (Cl) 0.8-1.5 at The Johns Hopkins University; RR = 1.6, 95% Cl 1.1-2.5 at the Memorial Sloan-Kettering Cancer Center; and RR = 2.5, 95% Cl 1.6-4.0 at the Mayo Clinic). Results suggest that mild atypia as detected by cytologic evaluation of sputum is an indicator of a modest elevation in risk of bronchogenic carcinoma.

Debunking myths about self-quitting. Evidence from 10 prospective studies of persons who attempt to quit smoking by themselves

This article examines data from 10 longterm prospective studies (N greater than 5,000) in relation to key issues about the self-quitting of smoking, especially those discussed by Schachter. When a single attempt to quit was evaluated, self-quitters' success rates were no better than those reported for formal treatment programs. Light smokers (20 or less cigarettes per day) were 2.2 times more likely to quit than heavy smokers. The cyclical nature of quitting was also examined. There was a moderate rate (mdn = 2.7%) of long-term quitting initiated after the early months (expected quitting window) of these studies, but also a high rate (mdn = 24%) of relapsing for persons abstinent for six months. The number of previous unsuccessful quit attempts was unrelated to success in quitting. Finally, there were few occasional smokers (slips) among successful long-term quitters. We argue that quitting smoking is a dynamic process, not a discrete event.

The association between depressive symptoms and mortality among older participants in the Epidemiologic Catchment Area-Piedmont Health Survey

The association between depression and two-year mortality risk was assessed in 1,606 elderly community participants in the 1982-83 Epidemiologic Catchment Area-Piedmont Health Survey. Two depression measures were formed from the Diagnostic Interview Schedule (DIS) depressive symptom items. Neither measure was associated with mortality in univariate or multiple logistic regression analyses. The adjusted relative risk of mortality comparing the lowest to highest levels of a three-level depression variable was 0.9 (95% confidence interval = 0.5-1.4). Similar results were obtained with other versions of the depression variables, with each depressive symptom category, and within sex, chronic disease, widowhood status, and age groups. These results indicate that depression does not increase mortality in elderly adults, but the short follow-up, sample characteristics, and operationalization of depression may have affected this association.

The effects of childhood parental death and divorce on six-month history of anxiety disorders

Duke Epidemiologic Catchment Area (ECA) data were used to examine the relationships between: (a) early childhood maternal death, paternal death, and parental separation/divorce, and (b) six-month DIS/DSM-III diagnoses of agoraphobia with and without panic attacks, simple phobia, social phobia, panic disorder, generalised anxiety disorder, and obsessive-compulsive disorder. Associations were found between: (a) maternal death and agoraphobia with panic attacks, and (b) parental separation/divorce and agoraphobia with panic attacks and panic disorder. The associations could not be explained by the effects of potentially confounding socio-demographic factors.

Epidemiology of depressive symptoms in young adolescents

Center for Epidemiologic Studies Depression Scales, completed by 677 junior high school students, were used to investigate the significance and measurement of depressive symptoms in young adolescents. Responses differentiated transient and more persistent symptoms. Few students noted the most persistent symptoms (less than 15% for any one item). Minority race, lower social economic status, lower school grade, family constellation, and poorer school progress were associated with higher depressive symptom scores. Findings from this study suggest that high persistent depressive symptomatology is not a universal adolescent experience and that persistent depressive symptoms may be associated with other adverse events.

A survey of smoking and quitting patterns among black Americans

A sample of adult Black policyholders of the nation's largest Black-owned life insurance company was surveyed in 1986 to add to limited data on smoking and quitting patterns among Black Americans, and to provide direction for cessation initiatives targeted to Black smokers. Forty per cent of 2,958 age-eligible policyholders for whom current addresses were available returned a completed questionnaire. Population estimates for smoking status agree closely with national estimates for Blacks age 21-60 years: 50 per cent never-smokers; 36 per cent current smokers; 14 per cent ex-smokers. Current and ex-smokers reported a modal low-rate/high nicotine menthol smoking pattern. Current smokers reported a mean of 3.8 serious quit attempts, a strong desire and intention to quit smoking, and limited past use of effective quit smoking treatments and self-help resources. Correlates of motivation to quit smoking were similar to those found among smokers in the general population, including smoking-related illnesses and medical advice to quit smoking, previous quit attempts, beliefs in smoking-related health harms/quitting benefits, and expected social support for quitting. Methodological limitations and implications for the design of needed Black-focused quit smoking initiatives are discussed.

Debunking myths about self-quitting: Evidence from 10 prospective studies of persons who attempt to quit smoking by themselves

This article examines data from 10 longterm prospective studies (N greater than 5,000) in relation to key issues about the self-quitting of smoking, especially those discussed by Schachter. When a single attempt to quit was evaluated, self-quitters' success rates were no better than those reported for formal treatment programs. Light smokers (20 or less cigarettes per day) were 2.2 times more likely to quit than heavy smokers. The cyclical nature of quitting was also examined. There was a moderate rate (mdn = 2.7%) of long-term quitting initiated after the early months (expected quitting window) of these studies, but also a high rate (mdn = 24%) of relapsing for persons abstinent for six months. The number of previous unsuccessful quit attempts was unrelated to success in quitting. Finally, there were few occasional smokers (slips) among successful long-term quitters. We argue that quitting smoking is a dynamic process, not a discrete event.

Health risk appraisal: review of evidence for effectiveness

Since its introduction some two decades ago, health risk appraisal (HRA) has become a standard offering in the health promotion repertoire. The technique's distinctive feature is its use of epidemiologic data to generate quantitative risk messages for the client. Yet despite the dedication and considerable investments that have gone into HRA's development, dissemination, and use, there is only limited empirical evidence that these quantitative risk messages have any effect on clients. There do not appear to be any formal studies of HRA's effect on participation in health promotion programs, although increasing recruitment is regarded as a major benefit of using HRA. There are few indications of HRA effects on health beliefs. Most positive reports of effects on behavior change come from uncontrolled studies; several randomized controlled trials have yielded ambiguous findings. Virtually no data exist concerning the impact of the quantitative risk messages that distinguish HRA from other assessment techniques and that have motivated the substantial efforts toward developing and refining HRA. HRA has evident appeal and is probably a useful health education device for middle-class, middle-aged, nonminority clients. It may well have desirable effects on health-related beliefs, attitudes, and behaviors when accompanied by counseling or education, but available evidence has not established its effectiveness. Given the difficulty of obtaining definitive evidence of the effectiveness of HRA and specifically of its use of quantitative risk projections, the need for such evidence is debatable. An adequately funded and reviewed research program to examine whether projections of absolute risk affect knowledge, beliefs, attitudes, and intention to change is recommended as the most fruitful next step. Epidemiologically based HRA procedures that provide feedback in terms of qualitative statements or relative risk may be a promising approach to prospective health assessment.

Social ties and mortality in Evans County, Georgia

In an attempt to replicate Berkman and Syme's study of social networks and mortality in Alameda County, California, the authors investigated the relationship between a social network index and survivorship from 1967 to 1980 in the Evans County, Georgia, cohort. They constructed an index modeled after the Berkman Social Network Index and tested it in race- and sex-specific proportional hazards models for 2,059 subjects who were examined in 1967-1969 during the Evans County Cardiovascular Epidemiologic Study. The present study emphasized a priori specification of the social network index and statistical hypothesis test. Descriptive analyses were consistent with a modest social networks effect (e.g., hazard ratio (95 per cent confidence interval) of 1.6 (1.2-2.2) ). Among white males, the age-adjusted hazard ratio comparing the lowest to the highest value of our six-level index was 2.0 (1.2-3.4), but control for potential confounders (principally cardiovascular disease risk factors) reduced this value to 1.5 (0.8-2.6). The social networks effect among white females, black males, and black females was weaker and clearly nonsignificant. Exploratory analyses suggested that marital status, church activities, and an alternate social network index predicted survivorship, but not in a dose-response fashion. Reduced survivorship among older subjects with few social ties was the most important feature of the data.

Habitual vigorous exercise and primary cardiac arrest: effect of other risk factors on the relationship

To determine if the relationship between habitual vigorous exercise and primary cardiac arrest (PCA) is modified by the presence of other risk factors, we investigated 133 male cases of PCA, 25-75 years of age, without prior heart disease or co-morbidity, and 133 controls, identified from the same community. Persons who did not engage in high-intensity leisure-time activity for more than 20 min per week were classified as non-vigorous. The risk of PCA was more than doubled for non-vigorous males, both in the presence and absence of other risk factors taken individually, i.e. age greater than or equal to 60, hypertension, cigarette smoking, obesity, and family history. The incidence of PCA attributable to lack of vigorous activity was greatest for older, hypertensive, or obese males; for each of these subgroups, it exceeded 19 cases/10,000 persons/yr. Efforts to discourage clinically healthy persons at risk of PCA from continuing to engage in vigorous exercise may be inappropriate.

Prevalence of self-reported depressive symptoms in young adolescents

To investigate the significance and measurement of depressive symptoms in young adolescents, 624 junior high school students were asked to complete the Center for Epidemiologic Studies Depression Scale (CES-D) during home interviews. In 384 usable symptom scales, item-scale correlations (most were above .50), inter-item correlations, coefficient alpha (.85), and patterns of reported symptoms were reasonable. Persistent symptoms were reported more often by Blacks, especially Black males. Prevalence of persistent symptoms in Whites was quite close to reported figures for adults, ranging from 1 per cent to 15 per cent in adolescent males and 2 per cent to 13 per cent in adolescent females. Adolescents reported persistent vegetative symptoms less often and psychosocial symptoms more often. Reports of symptoms without regard to duration were much more frequent in the adolescents, ranging from 18 per cent to 76 per cent in White males, 34 per cent to 76 per cent in White and Black females, and 41 per cent to 85 per cent in Black males. The results support the feasibility of using a self-report symptom scale to measure depressive symptoms in young adolescents. Transient symptoms reported by adolescents probably reflect their stage of development, but persistent symptoms are likely to have social psychiatric importance.

The use of epidemiologic data for personal risk assessment in health hazard/health risk appraisal programs

Health Hazard/Health Risk Appraisal (HHA/HRA) programs employ personal risk assessment as an educational and motivational technique to encourage the adoption of healthier lifestyles by health education clients. We have reviewed the scientific basis of of the risk assessments provided in HHA/HRA. There are severe limitations in both the data and the risk estimation procedures. Various undocumented assumptions enter into the projections; several key aspects are arbitrary. Proposals for improvement of the procedure generally require data that are not available. Attention has largely focused on increasing mathematical sophistication (e.g. adjustment for competing risks) while ignoring problems in accuracy of the client data from which projections are calculated and serious questions about the health education messages implicit in the appraisal results. Health Hazard/Health Risk Appraisal programs should be candid about the limitations of the technique. Use of appraisal results for evaluation purposes is questionable. The health education messages produced by such programs deserve attention, since their appropriateness, especially for clients who are not white, middle class and middle-aged, has not been established.

Use of a symptom scale to study the prevalence of a depressive syndrome in young adolescents

The entire student enrollment (n = 624) in a public junior high school in Raleigh, North Carolina were visited in their homes between October 1978 and February 1979. Eleven (2.9%) of 384 students completing the Center for Epidemiologic Studies self-report depression scale reported symptoms patterns consistent with the Research Diagnostic Criteria for major depressive disorder. These 11 subjects were concentrated in the top 12% of the distribution of symptom scores and had symptom prevalences exceeding those in the overall study population by a factor of three or more. Black males from low income households predominated. A self-report questionnaire may be usable to detect a depressive "syndrome" in young adolescents. The prevalence of such a syndrome is similar to prevalence estimates for adults and young adolescents, but considerably lower than estimates derived from total scale scores and cutoff points. A syndrome-oriented analytic approach for symptom scales should be explored as an alternative to the use of cutoff scores for epidemiologic studies of psychiatric disorders.

An assessment of health hazard/health risk appraisal

A state-of-the-art review of a widely-used health promotion technique, the health hazard/health risk appraisal (HHA/HRA), was conducted. The review included preparing a 212-item annotated bibliography, compiling an inventory of 217 programs that have used HHA/HRA, holding discussions with HHA/HRA developers and users, conducting formal site visits to 15 HHA/HRA programs, and consultation with experts on epidemiology, biostatistics, and behavioral science as well as developers and users of HHA/HRA. Programs use HHA/HRA primarily as a promotional device, as a tool for structuring education about health-related behaviors, and as a motivational device for stimulating behavioral change. The scientific basis for HHA/HRA risk predictions is problematic, but their arithmetic imprecision is of less concern than insufficiency of the scientific evidence for certain behavioral recommendations, and inaccuracies in client-supplied data. Widely-held beliefs in HHA/HRA's efficacy for motivating behavioral change cannot be substantiated from available evidence, nor can the assumed absence of adverse effects. The importance of this particular health promotion technique appears to have been exaggerated.