Sensitivity and specificity of mammographic screening as practised in Vermont and Norway.

OBJECTIVE: The aim of this study was to examine the sensitivity and specificity of screening mammography as performed in Vermont, USA, and Norway. METHODS: Incident screening data from 1997 to 2003 for female patients aged 50-69 years from the Vermont Breast Cancer Surveillance System (116 996 subsequent screening examinations) and the Norwegian Breast Cancer Screening Program (360 872 subsequent screening examinations) were compared. Sensitivity and specificity estimates for the initial (based on screening mammogram only) and final (screening mammogram plus any further diagnostic imaging) interpretations were directly adjusted for age using 5-year age intervals for the combined Vermont and Norway population, and computed for 1 and 2 years of follow-up, which ended at the time of the next screening mammogram. RESULTS: For the 1-year follow-up, sensitivities for initial assessments were 82.0%, 88.2% and 92.5% for 1-, 2- and >2-year screening intervals, respectively, in Vermont (p=0.022). For final assessments, the values were 73.6%, 83.3% and 81.2% (p=0.047), respectively. For Norway, sensitivities for initial assessments were 91.0% and 91.3% (p=0.529) for 2- and >2-year intervals, and 90.7% and 91.3%, respectively, for final assessments (p=0.630). Specificity was lower in Vermont than in Norway for each screening interval and for all screening intervals combined, for both initial (90.6% vs 97.8% for all intervals; p<0.001) and final (98.8% vs 99.5% for all intervals; p<0.001) assessments. CONCLUSION: Our study showed higher sensitivity and specificity in a biennial screening programme with an independent double reading than in a predominantly annual screening program with a single reading. ADVANCES IN KNOWLEDGE: This study demonstrates that higher recall rates and lower specificity are not always associated with higher sensitivity of screening mammography. Differences in the screening processes in Norway and Vermont suggest potential areas for improvement in the latter.

Effect of previous benign breast biopsy on the interpretive performance of subsequent screening mammography.

BACKGROUND: Most breast biopsies will be negative for cancer. Benign breast biopsy can cause changes in the breast tissue, but whether such changes affect the interpretive performance of future screening mammography is not known. METHODS: We prospectively evaluated whether self-reported benign breast biopsy was associated with reduced subsequent screening mammography performance using examination data from the mammography registries of the Breast Cancer Surveillance Consortium from January 2, 1996, through December 31, 2005. A positive interpretation was defined as a recommendation for any additional evaluation. Cancer was defined as any invasive breast cancer or ductal carcinoma in situ diagnosed within 1 year of mammography screening. Measures of mammography performance (sensitivity, specificity, and positive predictive value 1 [PPV1]) were compared both at woman level and breast level in the presence and absence of self-reported benign biopsy history. Referral to biopsy was considered a positive interpretation to calculate positive predictive value 2 (PPV2). Multivariable analysis of a correct interpretation on each performance measure was conducted after adjusting for registry, year of examination, patient characteristics, months since last mammogram, and availability of comparison film. Accuracy of the mammogram interpretation was measured using area under the receiver operating characteristic curve (AUC). All statistical tests were two-sided. RESULTS: A total of 2,007,381 screening mammograms were identified among 799,613 women, of which 14.6% mammograms were associated with self-reported previous breast biopsy. Multivariable adjusted models for mammography performance showed reduced specificity (odds ratio [OR] = 0.74, 95% confidence interval [CI] = 0.73 to 0.75, P < .001), PPV2 (OR = 0.85, 95% CI = 0.79 to 0.92, P < .001), and AUC (AUC 0.892 vs 0.925, P < .001) among women with self-reported benign biopsy. There was no difference in sensitivity or PPV1 in the same adjusted models, although unadjusted differences in both were found. Specificity was lowest among women with documented fine needle aspiration-the least invasive biopsy technique (OR = 0.58, 95% CI = 0.55 to 0.61, P < .001). Repeating the analysis among women with documented biopsy history, unilateral biopsy history, or restricted to invasive cancers did not change the results. CONCLUSIONS: Self-reported benign breast biopsy history was associated with statistically significantly reduced mammography performance. The difference in performance was likely because of tissue characteristics rather than the biopsy itself.

Factors associated with arm swelling after breast cancer surgery.

PURPOSE: As life expectancy improves for women with breast cancer, more women will be living with symptoms of lymphedema. This study reports the incidence of arm or hand swelling and associated risk factors in women with invasive breast cancer following surgery. METHODS: Data were obtained from baseline and follow-up interviews of women with invasive breast cancer (n = 145), and mammography and pathology records. The Kaplan-Meier method was used to estimate the probability of developing arm or hand swelling over time. Univariate and multivariate logistic regression analyses were conducted to identify risk factors for arm or hand swelling. RESULTS: Of women in this study, 38% self-reported arm or hand swelling. There was a significantly increased risk of arm swelling if women were under 50 years of age, had axillary node dissection, received chemotherapy, worked outside the home, and had a high household income. There was no association of body weight with swelling. A significantly decreased risk of arm swelling was found in women who were on treatment for high blood pressure. After adjustment for nodal dissection, only age had a significant independent effect. CONCLUSIONS: Our study highlights two important areas of future research that could reduce the incidence of lymphedema. There is a need to better understand the role that treatment for high blood pressure may play in protecting women from arm edema. Second, the potential effect of weight as a modifiable lymphedema risk factor needs to be studied in more detail in light of the conflicting results of different studies.

Identifying women at risk for inherited breast cancer using a mammography registry.

BACKGROUND: Women at risk for inherited breast cancer have been identified for intervention studies through newly diagnosed relatives or from volunteers with a family history. This pilot study tested the use of a mammography registry to identify women at risk. METHOD: Fifty women with first-degree relatives diagnosed as having breast cancer before age 45 were randomly selected from the Vermont Breast Cancer Surveillance System. Thirty-three women (66%) completed a phone interview that included a three-generation family pedigree of breast and ovarian cancers. RESULTS: Fifty-one percent of the women were at higher risk for inherited breast cancer based on the family history. Eighteen percent of the first-degree relatives' breast cancers were pathologically confirmed. CONCLUSION: Mammography registries that collect similar family history data may be used to identify women at risk for inherited breast cancer. Many intervention studies would require improved methods to obtain pathologic confirmation.

Current medicolegal and confidentiality issues in large, multicenter research programs.

The convenience of fast computers and the Internet have encouraged large collaborative research efforts by allowing transfers of data from multiple sites to a single data repository; however, standards for managing data security are needed to protect the confidentiality of participants. Through Dartmouth Medical School, in 1996-1998, the authors conducted a medicolegal analysis of federal laws, state statutes, and institutional policies in eight states and three different types of health care settings, which are part of a breast cancer surveillance consortium contributing data electronically to a centralized data repository. They learned that a variety of state and federal laws are available to protect confidentiality of professional and lay research participants. The strongest protection available is the Federal Certificate of Confidentiality, which supersedes state statutory protection, has been tested in court, and extends protection from forced disclosure (in litigation) to health care providers as well as patients. This paper describes the careful planning necessary to ensure adequate legal protection and data security, which must include a comprehensive understanding of state and federal protections applicable to medical research. Researchers must also develop rules or guidelines to ensure appropriate collection, use, and sharing of data. Finally, systems for the storage of both paper and electronic records must be as secure as possible.

The association of increased weight, body mass index, and tissue density with the risk of breast carcinoma in Vermont.

BACKGROUND: Etiologic studies of breast carcinoma have indicated that weight, body mass index (BMI), and breast tissue density are important determinants of a woman's risk for the disease. This study looked at the independent effects of these risk factors. METHODS: Data from the Vermont Breast Cancer Surveillance System (VBCSS), collected between May 1996 and November 1997, were used to identify 529 breast carcinoma cases with no prior history of the disease. Each case was matched to four randomly chosen women of the same age who had mammograms during the same time period and had no biopsy-confirmed breast carcinoma. Logistic regression was used to assess the effects of weight, BMI, and breast tissue density on breast carcinoma risk for pre- and postmenopausal women. RESULTS: Weight and BMI were found to be significantly associated with postmenopausal breast carcinoma after adjustment for breast density, and vice versa. The density-adjusted odds ratio for women weighing over 81 kg, relative to women weighing under 63 kg, was 2.1, with a 95% confidence interval (CI) of 1.3-3.2. Relative to women with breasts consisting entirely of fat, the weight-adjusted odds ratios for women with heterogeneously dense and extremely dense breasts were 2.3 (CI: 1.3-4.3) and 4.5 (CI: 1.9-10.6), respectively. CONCLUSIONS: Among postmenopausal Vermont women, weight, BMI, and breast density were independently associated with breast carcinoma risk. Because breast density and weight or BMI are inversely related, estimates of their independent effects should be used when evaluating a woman's risk for breast carcinoma.

The role of health professionals in a community-based program to help women quit smoking.

BACKGROUND: Health professionals are credible sources of smoking cessation advice. This study describes changes in health professionals' reported provision of smoking cessation counseling activities for women during a community health education project that took place in two intervention counties (I) and compares these to reports from health professionals in two similar comparison counties (C). METHODS: Specific smoking cessation activities reported by physicians (I n = 73, C n = 73), dentists (I n = 51, C n = 46), dental hygienists (I n = 38, C n = 44), family planning and WIC (Special Supplemental Food Program for Women, Infants and Children) counselors (I n = 14 C n = 16), and community mental health counselors (I n = 57, C n = 23) were assessed by mailed surveys at baseline, after 4 years of countywide interventions, and 2 years later. RESULTS: Compared with health professionals in the comparison counties, significant increases in smoking cessation training (P < 0.01) and in reported referral of women to stop smoking groups, support groups, and one-to-one support were noted for physicians, family planning, and WIC counselors (P < 0.001); in training and referral to stop smoking groups and support groups by dentists and dental hygienists (P < 0.05); and in referral to support groups by community mental health counselors (P < 0.05). Significant increases in setting quit dates (P < 0.05) and providing self-help materials (P < 0.01) were also noted for family planning and WIC counselors. These effects were no longer demonstrable 2 years after external support for the countywide interventions was withdrawn. CONCLUSIONS: We suggest that an important aspect of facilitating consistent smoking cessation advice and counseling from health professionals in the future will be the provision of a broader range of regularly available smoking cessation support systems within communities than is generally available at this time in the United States.

Life expectancy estimation with breast cancer: bias of the declining exponential function and an alternative to its use.

BACKGROUND: Life expectancy gain (LEG) is an outcome measure commonly estimated with a declining exponential function in a Markov model. The accuracy of such estimates has not been objectively evaluated. PURPOSE: To compare LEGs from declining exponential function estimates with those calculated from population data, using published screening mammography studies as examples. METHOD: SEER-based population data are used to compare LEG calculation with declining exponential function estimation and empiric population data in a new model, the "nested" Markov. RESULTS: Analyses of the LEG of mammographic screening based on the declining exponential function significantly overestimate LEGs for younger women and underestimate them for older women. Because of offsetting errors, all-age analyses paradoxically appear accurate. CONCLUSION: Declining exponential function estimates of LEGs for chronic diseases with low mortality rates and long time horizons are liable to significant bias, especially with limited age cohorts.

Community-based promotion of breast screening using small group education.

Small Group Education (SGE) to promote breast cancer screening was implemented in a community-wide program. Based on diffusion of innovations theory, SGE initially was directed toward women at higher occupation and education levels and then progressively shifted toward more vulnerable populations of women at risk of not getting screening. During the four-year intervention, 116 volunteers led SGE presentations, with 8,184 women participating in 740 groups at work sites, organizations, residences, and churches. High participation in SGE and positive participant responses suggest that delivery of SGE using a social diffusion model was an effective method for reaching women throughout the community.

Referral patterns for the evaluation of non-palpable breast abnormalities.

BACKGROUND: Non-palpable suspicious mammographic abnormalities require image-guided breast biopsies. In this study, we examined primary care physicians' knowledge of breast biopsy procedures for non-palpable lesions and referral patterns for breast biopsies; we also identified channels to disseminate information. METHODS: We mailed a baseline survey to all primary care physicians, surgeons, and radiologists in Vermont. RESULTS: Primary care physicians are more likely to refer for excisional rather than percutaneous biopsy. Unlike surgeons and radiologists who learned about these procedures through journals and professional meetings, primary care physicians' most common source of information was from radiologists. CONCLUSIONS: Information about indications for using percutaneous breast biopsy should be available in journals and at meetings to help primary care providers decide on the most appropriate algorithm of workup for patients with non-palpable suspicious breast abnormalities requiring biopsy.

Assessment of self-reward strategies for maintenance of breast self-examination.

This study examined the relative impact of different self-reward strategies on maintenance of breast self-examination (BSE) practice among 1649 women trained to do BSE. Training groups were randomized into four conditions: (a) self-reward instructions and materials delivered at the end of the BSE training session; (b) self-reward suggestions delivered through the mail each month, contingent upon the BSE performance; (c) external monetary rewards and self-reward suggestions delivered through the mail each month on an intermittent schedule, contingent upon BSE practice; and (d) a no-reward control condition. Follow-up assessments 12 months following training revealed a pattern of evidence in support of the benefits of external monetary rewards and self-reward prompts on BSE frequency and quality; however, it is likely that the value of that condition lies in the external reward component.

Modeling smoking cessation: exploring the use of a videotape to help pregnant women quit smoking.

This exploratory study examined the acceptability and efficacy of a videotape modeling smoking cessation as an adjunct to smoking cessation advice delivered during prenatal care. In a randomized controlled trial involving 60 women, we compared the delivery of brief smoking cessation advice and a tipsheet to the same advice and tipsheet plus provision of the videotape. Outcomes included opinions about content and acceptability of the videotape, and smoking behavior change during pregnancy. The most highly endorsed features of the videotape were seeing other women quitting smoking (77%), dealing with stress and bad feelings (69%), talking about what to do with urges to smoke (69%), and discussing ways to get support from families and friends (54%). The reported quit rate in the last month of pregnancy, validated by exhaled carbon monoxide levels, and including women lost to follow-up as smokers, was 19.2% in the intervention group and 0% in the comparison group (p = .02). This study suggests that the use of videotapes modeling smoking behavior change may increase the effectiveness of the assistance in quitting smoking that is generally available in obstetric and family practices or public maternity clinics.

Helping women quit smoking: baseline observations for a community health education project.

INTRODUCTION: Our objectives were (1) to examine the relationship between women's intention of stopping smoking in the next month and a broad range of mediating variables and (2) to assess the implications of these relationships for intervention components of a comprehensive community-wide health education program to help women quit smoking. METHODS: In preparation for the community-wide program to help women quit smoking, baseline data were collected through a random digit dialing telephone survey of 6,324 adult women, 18-64 years of age. RESULTS: At baseline, smoking prevalence, defined as smoking an average of one or more cigarettes per day, was 25.8% and showed clear relationships with age and income, but most strikingly with education, indicating the need for programs for women of childbearing age with low incomes and fewer years of schooling. Among female smokers, knowledge of the health effects of smoking; motivations toward quitting; confidence in controlling weight, or handling stress, anger or boredom; number of strategies named to cope when upset of angry; number of community smoking cessation resources named; perceptions of support for quitting; and perceptions of norms concerning women smoking varied significantly with level of intention to quit smoking in the next month. CONCLUSIONS: These relationships provided support for the broad range of health behavior change strategies proposed for this community-based program to help women quit smoking.

Barriers to condom use among women attending planned parenthood clinics.

Assessed condom use, barriers to condom use, oral contraceptive use, partnership status and STD history in 457 15-30 year-old women attending four family planning clinics. Subjects were classified into three condom use groups: Non Users (37%); Current Users (33%); and Past Users (30%). Factor analysis revealed five barriers to condom use: Partner's Perception, Peer's Perception, Pleasure/Intimacy, Communication, and Low Perceived Need. Multivariate analyses revealed significant group differences on only two barrier factors: Pleasure/Intimacy and Low Perceived Need. Low Perceived Need accounted for 13.5% of the variance in condom use. Women with low perceived need to use condoms were more likely to use oral contraceptives.

PIP: A survey of 457 female clients, 15-30 years old, recruited from 4 Vermont (US) Planned Parenthood clinics in 1990 identified low perceived need as a significant barrier to condom use. Although study subjects averaged 2.5 sexual partners in the preceding 2 years and 21.6% had a history of a sexually transmitted disease (STD), condoms were used an average of only 1.1 times out of the last 5 acts of intercourse. 37% of the clients had never used condoms, 30% were past users, and 33% had used condoms at least once during their last 5 sexual encounters. 82.1% of study subjects were current oral contraceptive (OC) users. Discriminant analysis identified 6 obstacles that predicted, cumulatively, 21.5% of the condom use category variance: low perceived need (13.5%), use of the pill (4.0%), number of sexual partners in the past 2 years (1.9%), age (0.8%), education (0.8%), and pleasure/intimacy (0.5%). These variables correctly identified 71% of condom nonusers, 65% of current users, and 18% of past users. When women were crudely divided into 2 categories based on estimated actual risk for STDs, there was no difference between the high and low risk groups in terms of perceived need score or condom use category. In addition, low perceived need was unrelated to knowledge, number of sexual partners, STD history, age, or education. There was, however, a positive association between low perceived need and OC use. These family planning clinic clients appear to be focused almost exclusively on pregnancy prevention rather than on a strategy that would confer simultaneous protection against STDs.

Mass media and school interventions for cigarette smoking prevention: effects 2 years after completion.

The long-term cigarette smoking prevention effects of mass media and school interventions were assessed. Adolescents in two communities received both mass media and school interventions; those in two matching communities received only school interventions. Surveys of 5458 students were conducted at baseline in grades 4 through 6 and 2 years after the 4-year interventions were completed, when students were in grades 10 through 12. Students exposed to the media-plus-school interventions were found to be at lower risk for weekly smoking (odds ratio = 0.62, 95% confidence interval = 0.49, 0.78) than those receiving school interventions only, indicating that the effects of the combined interventions persisted 2 years after the interventions' completion.

Prevention of cigarette smoking through mass media intervention and school programs.

OBJECTIVES: In this study we tested the ability of mass media interventions to enhance the efficacy of school cigarette smoking prevention programs. METHODS: For 4 years, students in one pair of communities received media interventions and school programs that had common educational objectives. Students in a matched pair of communities received only the school programs. The combined cohort of 5458 students was surveyed at baseline in grades 4, 5, and 6 and was followed up annually for 4 years. RESULTS: Significant reductions in reported smoking, along with consistent effects on targeted mediating variables, were observed for the media-and-school group. For cigarettes per week the reduction was 41% (2.6 vs 4.4); for smoking cigarettes yesterday the reduction was 34% (8.6% vs 13.1%); and for smoking in the past week the reduction was 35% (12.8% vs 19.8%). No effects were observed for substance use behaviors not targeted by the interventions. CONCLUSIONS: These results provide evidence that mass media interventions are effective in preventing cigarette smoking when they are carefully targeted at high-risk youths and share educational objectives with school programs.

Development of a smoking prevention mass media program using diagnostic and formative research.

The process of developing a mass media campaign to prevent smoking among adolescents is described in detail. This campaign supplements a school smoking prevention program and shares educational objectives with the school program but is otherwise independent. It comprises various television and radio 30- and 60-sec "spot" messages. The campaign development process includes identifying educational objectives and strategies for appealing to young people; conducting diagnostic surveys and focus groups to determine target audience interests and perceptions about smoking and media content; suggesting approaches to producers to create preliminary television and radio messages for testing; conducting formative pretests with target groups to select optimal messages and suggest improvements to those messages; producing final messages for media presentation; and developing a media exposure plan to place messages in local media at optimal times for reception by target audiences. The media campaign is being evaluated in a 5-year project with 5,500 adolescents in four communities to determine the additional effect of mass media over a school program alone in preventing smoking.