A case-control study of breast cancer and hormonal contraception in Costa Rica.

By 1981, 11% of married women in Costa Rica ages 20-49 years had used depot-medroxyprogesterone acetate (DMPA) and 58% had used oral contraceptives (OCs). Since 1977, the Costa Rican Ministry of Health has maintained a nationwide cancer registry. These circumstances provided an opportunity for a population-based, case-control study of DMPA, OCs, and breast cancer in Costa Rica. Cases were 171 women ages 25-58 years with breast cancer diagnosed between 1982 and 1984; controls were 826 women randomly chosen during a nationwide household survey. Cases and controls were interviewed with the use of a standard questionnaire covering their reproductive and contraceptive histories. Logistic regression methods were used to adjust for confounding factors. While few cases or controls had ever used DMPA, DMPA users had an elevated relative risk (RR) estimate of breast cancer of 2.6 (95% confidence limits = 1.4-4.7) compared with never users. However, no dose-response relationship was found; even the group of women who had used DMPA for less than 1 year had an elevated RR estimate (RR = 2.3; 95% confidence limits = 1.0-5.1). In contrast, OC users had no elevation in RR compared with never users (RR = 1.2; 95% confidence limits = 0.8-1.8). The results of the DMPA analysis are inconclusive. Before decisions are made on whether to continue providing this effective contraceptive method, other ongoing studies will need to confirm of refute these findings.

PIP: Depot-medroxyprogesterone acetate (DMPA) is used by approximately 2 million women world-wide. In Costa Rica, by 1981 11% of the married women had used DMPA. Although no definitive link between the use of DMPA and the development of cancer has been found, the possibility has been recognized as one of the reasons for the U.S food and Drug Administration denying approval of the drug. Since 1977, the Ministry of Health in Costa Rica has sustained a national cancer registry. The accuracy of the reporting of the registry was studied by comparing a sampling of gynecologic cancer cases in the year 1983 to the national registry. In examination of the records, an elevated relative risk of breast cancer for DMPA users was found (2.6), and an elevated relative risk for women who had even used DMPA for a short period of time (2.3). The failure to interview 1/3 of the cases, differences in detection and the misclassification of DMPA use contributed cumulatively to the belief that a positive connection between breast cancer and DMPA use could otherwise be drawn. In contrast to the association found between DMPA ever use and breast cancer, no connection was found between OC use and the incidence of breast cancer. However, due to the small number of DMPA users recorded and the void of complete and accurate recorded information, the study results remain inconclusive.

The effect of using different reference dates for control exposure measurement on relative risk estimates in a case-control study.

In case-control studies in which case and control enrollment periods are not identical, exposure status for time-dependent variables is often measured relative to a reference date. Using data from a case-control study of the relation between cervical cancer and oral contraceptive (OC) use in which control enrollment began 6 months after the end of case enrollment, we evaluated the effect on odds ratios from using five different reference dates to determine the controls' exposure status. The choice of reference date had little effect on the odds ratios in this study. Reference dates for time-dependent exposure variables should be considered carefully in studies when case and control enrollment periods are not identical.

Cervical cancer risk and use of depot-medroxyprogesterone acetate in Costa Rica.

The relationship between cervical cancer and the use of depot-medroxyprogesterone acetate (DMPA) was examined in a nationwide case-control study in Costa Rica. Cases were women ages 25-58 years of age with invasive squamous cell cancer (N = 149) or carcinoma in situ (CIS, N = 415) reported by the National Tumor Registry during 1982-84. Controls (N = 764) were randomly selected during a nationwide household survey. Using logistic regression, we adjusted for known risk factors for cervical cancer. DMPA use was associated with a risk of CIS of 1.1 (95% confidence interval 0.6-1.8) and a risk of invasive cancer of 1.4 (95% confidence interval 0.6-3.1). The slightly elevated risks observed may be the result of chance or a detection bias. One limitation of this study is that few women had used DMPA for longer than two years.

PIP: A nationwide case-control study was conducted in Costa Rica in 1984-85 to examine the association between depot-medroxyprogesterone acetate (DMPA) and cervical cancer. Cases, restricted to women 25-58 years of age at the time of diagnosis, were women with invasive squamous cell cancer (n = 149) or carcinoma in situ (CIS, n=415) reported by the National Tumor Registry during 1982-84. The 764 controls were randomly selected during a nationwide household survey. On average, the CIS cases were younger than controls; the invasive cases were older than controls. Both case groups were more likely than controls to be of low socioeconomic status, to have become sexually active at a young age, to report a history of a sexually transmitted disease or pelvic inflammatory disease, and to report having 3 or more partners in their lifetime. Ever users of DMPA had a risk of CIS of 1.1 when compared with never users. Women who 1st used DMPA before age 30 had a CIS risk of 0.6 whereas users who began use after age 39 had a risk of 2.0. Both of these risk estimates were based on small numbers of users. Ever users of DMPA had a risk of invasive cancer of 1.4 when compared with never users, but all estimates for invasive cancer were based on only 10 cases who reported use of DMPA. Few of the women had used DMPA for longer than 2 years.

Diarrhoeal disease in Bangladesh: epidemiology, mortality averted and costs at a rural treatment centre.

The basic epidemiology of acute diarrhoeal disease seen at a rural Bangladesh hospital in 1975 is reviewed. V. cholerae 01 was isolated from 28% of 1 964 patients. Significant differences in hospitalisation rates were observed between males and females in several age groups. Overall hospital case fatality was 9/1000 cases. We estimate that approximately a quarter to half of the hospitalised patients would have died had no rehydration therapy been available. The region's total mortality was reduced by approximately 7%-15%, at a cost of United States $0.14 per capita. Mortality from acute diarrhoeal diseases was greatly reduced for all age groups, and total mortality and mortality from all diarrhoeal diseases were particularly reduced for young children and young adults. Rehydration therapy used in a field hospital was apparently highly effective in reducing general mortality and mortality from acute diarrhoeal diseases.

Herpes simplex virus type 2 antibodies: high prevalence in monogamous women in Costa Rica.

We studied the prevalence of antibody to Herpes simplex virus types 1 and 2 (HSV-1 and HSV-2) in 766 randomly selected Costa Rican women 25-59 years of age in a national household survey in 1984-1985. Overall, 97.1% were seropositive for HSV-1 and 39.4% for HSV-2. Only 1.1% of HSV-2 seropositive women gave a history of symptomatic genital herpes. HSV-2 virus antibody increased with age and with the number of lifetime sexual partners. HSV-2 seroprevalence among women who reported only 1 lifetime sexual partner was almost twice as high as the prevalence among women who denied sexual experience (30.5% vs. 17.7%) and reached 79.2% among women with greater than or equal to 4 partners. HSV-2 seroprevalence was lower among women whose partners used condoms: 28.9% for those who had used condoms for at least 2 years vs. 44.3% for those who never used condoms.

Preventing hepatitis B in people in close contact with hepatocellular carcinoma patients.

OBJECTIVE: To determine the prevalence of testing for hepatitis B virus (HBV) infection in the clinical management of primary liver cancer (hepatocellular carcinoma). METHODS: The authors reviewed the records of 78 patients treated for hepatocellular carcinoma in hospitals in the Puget Sound area in 1988 and early 1989 and reviewed all 1990 U.S. death certificates on which primary liver cancer was listed. RESULTS: The records of 50 (64%) of 78 hepatocellular carcinoma patients contained no evidence that the patient's hepatitis B surface antigen (HBsAg) status had been determined. In addition, of 4353 people who died in 1990 for whom the diagnosis of primary liver cancer was listed on the death certificate, HBV infection was also listed for only 136 (3%), much less than expected based on case series. CONCLUSIONS: Many patients with hepatocellular carcinoma are not tested for HBV infection, suggesting that their close contacts are also not evaluated for HBV infection and the need for vaccination. Hepatitis B vaccination of close personal contacts of HBV-infected hepatocellular carcinoma patients is an important strategy for preventing HBV transmission.

The prevalence of selected risk factors for chronic disease among American Indians in Washington State.

Despite great improvements in recent decades, the health status of American Indians continues to lag behind that of other Americans. Continued health improvement will depend largely on changes in individual behavior. Until recently, however, few data existed on health risk behaviors among American Indians. We conducted personal interviews among the adult population of an Indian Health Service Unit in Washington State to estimate the prevalence of some health risk behaviors. This analysis focuses on three of the many topics covered in the survey: tobacco use, alcohol consumption, and weight. Cigarette smoking was more prevalent among both men and women than it was in the general population in the same area with 43% of men and 54% of women among the American Indians interviewed reported that they currently smoked. However, they tended to smoke much less heavily than smokers in the general population. Smokeless tobacco use was concentrated among young men, with the overall prevalence similar to that found in the general population. Acute heavy drinking was found to be common with 40% of men and 33% of women reporting this behavior for the previous month. The prevalence of substantial overweight was 45% among men and 43% among women, considerably higher than in the general population. Tribal leaders and the Indian Health Service are using the findings to design disease prevention and health promotion activities. In addition to providing valuable information about the surveyed populations, the survey served as a pilot for similar studies of other American Indian groups.

A lifetable analysis of sterilization failure: data from the Profamilia Clinic, Bogota, Colombia.

Sterilization failure rates were computed using lifetable methods for sterilizations occurring between 1973 and 1982 in the Profamilia family planning clinic in Bogota, Colombia. Out of a total of nearly 45,000 sterilizations occurring during this period 503 sterilization failures were detected. Comparing methods, laparoscopy with the silastic band method had a significantly higher rate of failure, 1.5% after 5 years compared to 0.9% for laparoscopy with cautery and 0.6% for minilaparotomy.

Analysis of sterilization failure in Brazil.

A study of 13,423 female sterilization procedures performed from 1981 to 1984 in Rio de Janeiro, Brazil, was conducted to determine the level of sterilization failure. The lifetable cumulative failure rate was 0.54 at 12 months per 100 initial sterilizations, increasing to 1.04 at 48 months. Results of a multivariate analysis indicated that the differential in the rate of sterilization failure by woman's age at sterilization at 12 and 24 months was statistically highly significant. However, the differential rate of failure by the other variables such as whether sterilized during a training period, number of sterilizations per surgeon per day, and year of sterilization were not statistically significant.

PIP: To determine the level of sterilization failure, an analysis of the 13,423 female sterilization procedures carried out in 1981-84 at a primary care center in Rio de Janeiro was performed. 97% of these procedures were performed with a laparoscope, and a band was used for 98% of occlusions. 144 women reported a pregnancy after their sterilization procedure; of these, 22 were defined as occurring before the surgery (luteal phase) and were excluded from the life-table analysis. The cumulative failure rate was 0.54/100 sterilizations at 12 months and 1.04/100 procedures at 48 months. Parity, method of sterilization, and occlusion technique were not correlated with sterilization outcome. However, logistic regression analysis indicated that the rates of sterilization failure at 12 and 24 months were consistently lower for older women (age 30 years and above) than women in the 17-29-year age group. (p0.01). The number of sterilizations performed per day was also a factor in sterilization failure, but this association was not statistically significant. 5.7% of the sterilization failures resulted in ectopic pregnancies. Overall, these findings are comparable to the failure rate in other countries. The occurrence of 22 luteal phase pregnancies in this study highlights the importance of thorough preoperative counseling and examination. It is recommended that contraception should be used in the cycle prior to sterilization to reduce this risk.

On publishing in an agency setting.

Writing journal articles quite often becomes a low priority for public health professionals in a busy agency setting. Despite the obstacles, an agency setting offers many opportunities to enhance public health knowledge. Opportunities for publication in an agency setting are reviewed, with examples of citations from the published literature.

Fertility change in Costa Rica 1960-84: analysis of retrospective lifetime reproductive histories.

Lifetime reproductive histories of a 1984-85 nationally representative sample of 870 women aged 25-59 years provided data to describe the evolution of fertility, contraception, breast-feeding, and natural fecundability in Costa Rica between 1960 and 1984. The contraceptive prevalence rate increased from 23% in 1965 to 58% in 1975 and 66% in 1984. Duration of breast-feeding was stable during the 1960s, decreased in the early 1970s, and increased after about 1976. Fecundability among women who did not practise contraception was lower than expected and declined between 1960 and 1975, probably because of selection effects. Despite a high consistency between estimations from the reproductive histories and other sources of data, some suggestion of omissions of short periods of contraceptive use in the distant past was detected. The survey may have reduced recall errors by using a calendar that summarizes major life events together. The analysis demonstrated the feasibility and usefulness of asking for lifetime reproductive histories in fertility surveys in developing countries.

PIP: Lifetime reproductive histories of a 1984 through 1985 nationally representative sample of 870 women aged 25 through 59 years provided data to describe the evolution of fertility, contraception, breast feeding, and natural fecundity in Costa Rica between 1969 and 1984. The contraceptive prevalence rate increased from 23% in 1965 to 58% in 1975 and 66% in 1984. Duration of breastfeeding was stable during the 1960s, decreased in the early 1970s, and increased after about 1976. Fecundability among women who did not practice contraception was lower than expected and declined between 1960 and 1975, probably because of the selection effects. Despite a high consistency between estimations from the reproductive histories and other sources of data, some suggestion of omissions of short periods of contraceptive use in the distant past was detected. The survey may have reduced recall errors by using a calendar that summarizes major life events together. The analysis demonstrated the feasibility and usefulness of asking for lifetime reproductive histories in fertility surveys in developing countries. Retrospective information gathered on 900 women permitted reconstruction of the results in a a period of dramatic changes. However, Costa Rica may be somewhat exceptional among developing countries because of its high levels of literacy. Some of the few, older, illiterate women may have found a life history calendar difficult to decipher, but others seemed to grasp the approach as easily as did the literate men.

Reproductive history and breast cancer in a population of high fertility, Costa Rica, 1984-85.

The relationship between breast cancer and women's reproductive history in Costa Rica was analyzed using logistic regression methods on data from 171 breast cancer cases and 826 population-based controls aged 25-58 years. The risk of breast cancer in nulliparous women under age 45 was 3 times that for parous women in the same age group. Women over 44 years of age with a parity greater than 4 had a risk of breast cancer of 0.3 compared to women of the same age but with a parity of 1-4. Neither breast-feeding nor birth interval showed an overall association with breast cancer independent of parity. Women with early age at first birth had a lower relative risk of breast cancer than women aged 20-24 at first birth, but only in two subgroups--women aged 45 and over and women with parity 1-4. Women without a completed pregnancy in the last 20 years had an elevated relative risk. However, results are not conclusive because some information is probably distorted by recall errors. Declines in fertility rates in the 1960s and 1970s may result in an increase of 30% in breast cancer incidence in Costa Rica between 1980 and the year 2000, according to the relative risks found in this study. In contrast, the effect of childlessness will probably not produce significant changes in national breast cancer trends.

Screening practices for cervical and breast cancer in Costa Rica.

Cervical cancer and breast cancer are leading causes of cancer-related morbidity and mortality in Costa Rica. This article reports results of an evaluation of cervical and breast cancer screening practices among Costa Rican women 25 to 58 years old that was based on a nationwide 1984-1985 survey. The evaluation showed that while Pap smears were widely used to screen for cervical cancer, many women did not have their first cervical smear or gynecologic examination until age 30, and that cervical cancer screening was less common among certain high-risk groups, including women with multiple sexual partners and those with high parity. Less than half the women surveyed reported having had a breast examination by a health care provider. Utilization of both cervical cancer and breast cancer screening examinations could be increased by targeting inadequately screened high-risk women through the existing health care system.

Detection of endotoxemia with the Limulus test: preliminary studies in severely malnourished children.

Eighteen Peruvian children with protein-calorie malnutrition were studied to evaluate the usefulness of the limulus assay for endotoxin in detecting gram-negative sepsis. Nine of the children had at least one positive Limulus assay, and eight of this group had bacteriologic cultures indicative of gram-negative infection. Four of these nine children with positive Limulus assays died, whereas only one of the nine children with negative assays died. This preliminary study suggests the usefulness of the Limulus assay as an adjunct to bacteriologic cultures in the early detection of significant gram-negative infection in severely malnourished children.