Pregnancy planning and pre-conception counseling. The PRAMS Working Group

OBJECTIVE

To estimate the percentage of women with one or more of four potentially modifiable risks who could have availed themselves of pre-conception counseling.

METHODS

We defined pre-conception counseling to be consultation that occurs shortly before a couple attempts conception. Thus, we assumed that to obtain pre-conception counseling, a woman must plan her pregnancy. We used data from a population-based survey of 12,452 new mothers in four states who delivered babies during 1988-1990. Mothers were contacted 3-6 months after delivery and asked about pre-conception behaviors and the planning status of their pregnancies. We estimated the percentage of women who planned their pregnancies and had an indication for pre-conception counseling related to smoking, drinking, being underweight, or delaying initiation of prenatal care.

RESULTS

State-specific response rates ranged from 68-84%. Sixty percent of mothers reported that their pregnancies were planned. In general, mothers with unintended pregnancies were more likely to have an indication for pre-conception counseling than mothers with planned pregnancies. Thirty-eight percent of all mothers planned their pregnancies and had one or more indications for pre-conception counseling. An additional 30% had one or more indications for counseling but did not have a planned pregnancy.

CONCLUSIONS

Despite the limited range of indications for counseling that we considered, a substantial percentage of women potentially could have used counseling. A similar percentage of women could have benefited from family planning services.

Smoking, pregnancy, and source of prenatal care: results from the Pregnancy Risk Assessment Monitoring System. The Pregnancy Risk Assessment Monitoring System Working Group

OBJECTIVE

To assess the impact of current smoking intervention efforts and to target future efforts by describing the relationships between maternal smoking, smoking cessation, and source of prenatal care.

METHODS

We used population-based data from 6319 mothers who delivered live-born infants during 1988 and 1989 in Maine, Michigan, Oklahoma, and West Virginia. The number of women sampled per state ranged from 1490-2659; state-specific response rates ranged from 66-84%. Analysis weights adjusted for selection probability and non-response.

RESULTS

The prevalences of maternal smoking before, during, and after pregnancy among women receiving publicly funded prenatal care were 2.3-3.4 times the comparable prevalences among privately insured women receiving prenatal care from private providers. Although many smokers reduced or quit smoking during pregnancy, most resumed or increased their smoking to nearly pre-pregnancy levels by 3-6 months postpartum.

CONCLUSIONS

Interventions should target the very high levels of smoking among the 27% of women receiving publicly funded prenatal care. However, from a population perspective, the greatest potential for reduction in smoking is among patients of private providers, who care for 61% of pre-pregnancy smokers.

Trends in obstetric operative procedures, 1980 to 1987

OBJECTIVES

Increasing rates of cesarean deliveries have received widespread attention in recent years, as concern in the United States about unnecessary surgical procedures has increased. However, little information has been published on the national trends of other operative obstetric procedures occurring during deliveries.

METHODS

We analyzed data from the National Hospital Discharge Survey to examine trends in the use of forceps, vacuum extraction, and cesarean section from 1980 through 1987.

RESULTS

The rate of cesarean sections increased by 48%, while the rate of forceps procedures declined by 43%. Although the risk of cesarean section was significantly increased for older women, the risk of forceps and vacuum extraction procedures did not vary by age. Women with private insurance were significantly more likely to receive a cesarean section (rate ratio [RR] = 1.2), forceps procedure (RR = 1.7), and vacuum extraction procedure (RR = 1.8) than were women without private insurance.

CONCLUSIONS

As pressure mounts to decrease the national cesarean section rate from 24% to 15% by the year 2000, attention should also be given to surveillance of other operative delivery procedures.

Hospitalization for pregnancy complications, United States, 1986 and 1987

OBJECTIVE

The purpose of our analysis was to provide a national overview of the magnitude of the public health burden associated with inpatient care for pregnancy complications.

STUDY DESIGN

We analyzed data from the National Hospital Discharge Survey for 1986 and 1987. We calculated ratios of hospitalizations for pregnancy complications for every 100 hospitalizations involving a birth. Standard errors for these ratios were calculated with RATIOEST, and relative ratios with 95% confidence intervals were calculated for subgroups of interest.

RESULTS

We found that for every 100 hospitalizations involving a birth, there were 22.2 nondelivery hospitalizations for pregnancy complications (14.6 antenatal complications, 7.6 pregnancy loss complications). These ratios were higher for black than for white women (relative ratio 1.4, 95% confidence interval 1.2 to 1.6). The effects of marital status, age, and insurance coverage differed between black and white women, and mean length of stay was longer for black than for white women.

CONCLUSION

Hospitalization for pregnancy complications is far more common than is widely appreciated and is more frequent among black than white women.

Smoking during pregnancy: prevalence, effects, and intervention strategies

Smoking prevalence rates have been declining in the United States, but an estimated 25 percent of pregnant women continue to smoke. Smoking during pregnancy is considered one of the leading, preventable causes of low birthweight. Research attributes 21 to 39 percent of low birthweight to smoking during pregnancy, although the exact mechanism of the effect is not completely understood. Several well-designed studies have shown that pregnant smokers are more likely to stop smoking if they are provided with systematic interventions. This overview describes adverse consequences, prevalence, possible mechanisms of action, and prenatal smoking-cessation programs that have proved effective. A five-step approach is outlined for clinicians who want to counsel their prenatal clients.

Trends in alcohol consumption by pregnant women. 1985 through 1988

To examine trends in alcohol consumption among pregnant women, we examined data collected from 21 states participating in the Behavioral Risk Factor Surveillance System for 4 consecutive years: 1985 through 1988. Overall, 429 (25%) of 1712 pregnant women and 19,903 (55%) of 36,057 nonpregnant women 18 to 45 years of age reported using alcohol in the previous month. Pregnant women who used any alcohol reported consuming a median of four drinks per month, whereas nonpregnant women who used any alcohol reported nine. The prevalence of alcohol consumption among pregnant women declined steadily, from 32% in 1985 to 20% in 1988, but the median number of drinks per month for pregnant women who drank did not change. No decline was observed among the less educated or those under the age of 25 years. In 1988, the prevalence of alcohol use among pregnant women remained highest among smokers (37%) and the unmarried (28%). Although the overall consumption of alcohol by pregnant women in the United States appears to be declining, special efforts are needed to reduce alcohol use among pregnant women who are smokers, unmarried, less educated, or younger, women who may already be at high risk of a poor pregnancy outcome.

Smoking before, during, and after pregnancy

We report the first national data on smoking before, during, and after pregnancy. Estimates are based on the 1986 Linked Telephone Survey that reinterviewed 1,550 White women 20-44 years of age who were respondents to the 1985 National Health Interview Survey. An estimated 39 percent of White women who had smoked before pregnancy quit smoking while pregnant (27 percent when they found out they were pregnant and 12 percent later during pregnancy). Women with less than 12 years of education were five times as likely to smoke and one-fourth as likely to quit as those with 16 or more years of education. Women who smoked more than one pack of cigarettes per day before pregnancy were one-fifth as likely to quit as those smoking less. Of the women who quit, 70 percent resumed smoking within one year of delivery. Of those who relapsed, 67 percent resumed smoking within three months of delivery and 93 percent within six months. There is little evidence of educational differentials in relapse rates. The fact that relapse remains high suggests that while health of the fetus is a strong influence on women's smoking habits, women may be less aware of the effect of passive smoke on the infant.

Outrunning the risks: a behavioral risk profile of runners

There is a need to assess better the relationship between physical activity and other health behaviors through population-based studies. Using the state-based Behavioral Risk Factor Surveillance System, we examined the behavioral risk factors of smoking, alcohol use, hypertension detection, obesity, seat-belt use, and physical activity in 2,412 runners and 26,538 nonrunners. Our analyses demonstrated marked differences in behavioral risk profiles between runners and nonrunners. Runners, regardless of the amount of running, were more likely to be nonsmokers, be of normal weight, be normotensive, and regularly use seat belts than were nonrunners of similar age and sex. Patterns of alcohol use were not different when comparing male runners with male nonrunners. However, female runners were more likely to drink and drive and to use alcohol on a chronic basis compared to their nonrunning counterparts. The "runner's lifestyle" may convey a certain level of protection from chronic disorders that are associated with these risk factors. However, further prospective studies are needed to examine in more detail the relationship of running to the risks and/or benefits for improved health.

Predicting lower-extremity injuries among habitual runners

This prospective study of 583 habitual runners used baseline information to examine the relationship of several suspected risk factors to the occurrence of running-related injuries of the lower extremities that were severe enough to affect running habits, cause a visit to a health professional, or require use of medication. During the 12-month follow-up period, 252 men (52%) and 48 women (49%) reported at least one such injury. The multiple logistic regression results identified that running 64.0 km (40 miles) or more per week was the most important predictor of injury for men during the follow-up period (odds ratio = 2.9). Risk also was associated with having had a previous injury in the past year (odds ratio = 2.7) and with having been a runner for less than 3 years (odds ratio = 2.2). These results suggest that the incidence of lower-extremity injuries is high for habitual runners, and that for those new to running or those who have been previously injured, reducing weekly distance is a reasonable preventive behavior.

The box plot: a simple visual method to interpret data

Exploratory data analysis involves the use of statistical techniques to identify patterns that may be hidden in a group of numbers. One of these techniques is the "box plot," which is used to visually summarize and compare groups of data. The box plot uses the median, the approximate quartiles, and the lowest and highest data points to convey the level, spread, and symmetry of a distribution of data values. It can also be easily refined to identify outlier data values and can be easily constructed by hand. We apply box plots to tabular data from two recently published articles to show how readers can use box plots to improve the interpretation of data in complex tables. The box plot, like other visual methods, is more than a substitute for a table: It is a tool that can improve our reasoning about quantitative information. We recommend that the box plot be used more frequently.

The Surgeon General's warnings in outdoor cigarette advertising. Are they readable?

Outdoor advertising media represent a major vehicle by which cigarette companies promote their products. We investigated the readability of the Surgeon General's warning in cigarette advertisements (ads) in two outdoor media: billboards and taxicab ads. In an experiment in metropolitan Atlanta under typical driving conditions, observers were able to read the entire health warning on 18 (46%) of 39 street billboards but on only two (5%) of 39 highway billboards. In contrast, the content of the ads (ie, brand name, other wording, and notable imagery) could be recognized under the same conditions on more than 95% of the billboards. In a similar study of 100 taxicab cigarette ads in New York City, observers were unable to read the health warning in any of the ads but were able to identify the brand name in all ads and notable imagery in 95% of the ads. Significant differences between the readability of the warning and identification of the advertising content persisted even when partially read warnings were considered to have been read. We conclude that the Surgeon General's warning is not readable in its current form in the vast majority of billboard and taxicab ads. Factors contributing to unreadability include the small size of the letters, the excessive length of the warnings, the distance between the viewers and the ads, and movement between the viewers and the ads.

Comparing the prevalence of smoking in pregnant and nonpregnant women, 1985 to 1986

The 1990 health objectives for the nation state that pregnant women should be only half as likely to smoke as nonpregnant women. To assess progress toward meeting this objective, we used cross-sectional data from the 26 states in the Behavioral Risk Factor Surveillance System in 1985 and 1986. We compared the prevalence of self-reported smoking among pregnant (N = 836) and nonpregnant (N = 18,025) women aged 18 to 45 years. Overall, pregnant women were 70% as likely to be current smokers as nonpregnant women (prevalence ratio, 0.7; 95% confidence interval, 0.6 to 0.8), while blacks showed the largest pregnancy-associated reduction in the prevalence of smoking (prevalence ratio, 0.5; 95% confidence interval, 0.3 to 0.9). Most of the difference in smoking prevalence occurred not because pregnant women were less likely to have ever smoked, but because pregnant women were more likely to have quit smoking than nonpregnant women. However, unmarried pregnant white women were 40% more likely to smoke than their nonpregnant counterparts (prevalence ratio, 1.4; 95% confidence interval, 1.1 to 1.7). We conclude from this analysis that the 1990 health objective for smoking among pregnant women is unlikely to be achieved. Clinicians providing care to pregnant women need to pay increased attention to smoking cessation.

Smoking by blacks and whites: socioeconomic and demographic differences

Using data from the 1985 National Health Interview Survey for persons aged 25-64 years, we controlled simultaneously for socioeconomic status (SES), demographic factors, and race in multivariate logistic regression analyses. We found that the odds of ever smoking are not higher for Blacks compared with Whites, when the other variables are controlled. By contrast, the odds of heavy smoking for Blacks are far less than for Whites, while Blacks are significantly less likely than Whites to quit smoking regardless of SES or demographic factors. Smoking cessation and prevention programs must be planned with these behavioral, SES, and demographic differences in mind.

Unintended laparotomy associated with laparoscopic tubal sterilization

Although the complication rate for laparoscopic tubal sterilization is generally low, laparotomy is sometimes necessary to complete the sterilization or manage complications. To better characterize factors that predispose women to unintended laparotomy, we analyzed data from the Collaborative Review of Sterilization. Of the 5027 women undergoing laparoscopic tubal sterilization, 12 had unintended laparotomies to manage complications, whereas 39 women had unintended laparotomies because of technical inability to complete the laparoscopic procedure. Women with prior abdominal or pelvic surgery had an increased risk of unintended laparotomy (relative risk = 10.2, 95% confidence interval = 5.3 to 19.7). Women with a history of intrauterine device use or pelvic inflammatory disease had elevated risks that were not statistically significant (relative risk = 2.2 and 1.5, respectively). Comparative studies of alternative surgical approaches for tubal sterilization are needed to formulate recommendations for women who may be at increased risk of unintended laparotomy associated with the laparoscopic approach.

The relative impact of smoking and oral contraceptive use on women in the United States

Women who smoke and use oral contraceptives (OCs) are at increased risk for cardiovascular and cerebrovascular disease. To study the prevalence of smoking and OC use and other behaviors affecting health, 28 states and the District of Columbia conducted telephone surveys during 1981 through 1983. More than 22,000 US adults were interviewed, of whom 5779 women aged 18 to 44 years were studied. Data were weighted to represent the US population. Overall, 7.4% of US women aged 18 to 44 years reported smoking and using OCs; 1.1% reported smoking 25 or more cigarettes per day while using OCs. Although women aged 18 to 24 years were most likely to smoke and use OCs, combined smoking and OC use contributed substantially to the number of excess cases of myocardial infarctions occurring among US women aged 35 to 44 years. However, regardless of OC use, smoking accounted for most of the excess cases. Therefore, health care providers need to intensify their efforts to reduce smoking among their patients.

Community-based exercise intervention: Zuni Diabetes Project

Non-insulin-dependent diabetes mellitus (NIDDM) is a serious health problem among the Zuni Indians of New Mexico. In July 1983, Indian Health Service personnel initiated a community-based exercise program designed to help control NIDDM in the community. To retrospectively evaluate the effects of the exercise program, the medical records of 30 participants with NIDDM were compared with the medical records of 56 nonparticipants with NIDDM matched by age, sex, health-care provider, and duration of NIDDM. From 1 July 1983 through 1 October 1985, participants had a mean weight loss of 4 kg, whereas nonparticipants had a mean weight loss of 0.9 kg (P less than .05). Participants' fasting blood glucose values dropped by a mean of 43 mg/dl, compared to a mean drop of 2 mg/dl among the nonparticipants (P less than .05). Participants were significantly more likely than nonparticipants to have stopped their hypoglycemic medication (relative risk 4.2) and to have decreased their medication dosage (relative risk 2.2). These results suggest that participation in a community-based exercise program can produce significant weight loss and improvement in glycemic control among a group of Native Americans with NIDDM.

Cigarette smoking and the risk of epithelial ovarian cancer

Cigarette smoking may affect each of the currently proposed mechanisms of ovarian carcinogenesis. Whether cigarette smoking has any effect on the development of ovarian cancer has not been adequately evaluated. To study this issue, the authors examined data from the Cancer and Steroid Hormone Study, a multicenter, case-control study of gynecologic cancers conducted between December 1, 1980, and December 31, 1982, in eight geographic areas of the United States. This analysis utilized data on 494 women with newly diagnosed epithelial ovarian cancer and 4,238 population-based control women 20-54 years of age. There was no association of epithelial ovarian cancer with dose of cigarette smoking, age smoking started, time since smoking started, or time since smoking last occurred. Simultaneous adjustment for age, parity, history of oral contraceptive use, and other potentially confounding factors did not alter these results.

Physical activity and the incidence of coronary heart disease

Our review focuses on all articles in the English language that provide sufficient data to calculate a relative risk or odds ratio for CHD at different levels of physical activity. The inverse association between physical activity and incidence of CHD is consistently observed, especially in the better designed studies; this association is appropriately sequenced, biologically graded, plausible, and coherent with existing knowledge. Therefore, the observations reported in the literature support the inference that physical activity is inversely and causally related to the incidence of CHD. The two most important observations in this review are, first, better studies have been more likely than poorer studies to report an inverse association between physical activity and the incidence of CHD and, second, the relative risk of inactivity appears to be similar in magnitude to that of hypertension, hypercholesterolemia, and smoking. These observations suggest that in CHD prevention programs, regular physical activity should be promoted as vigorously as blood pressure control, dietary modification to lower serum cholesterol, and smoking cessation. Given the large proportion of sedentary persons in the United States (91), the incidence of CHD attributable to insufficient physical activity is likely to be surprisingly large. Therefore, public policy that encourages regular physical activity should be pursued.

Postmenopausal smoking, estrogen replacement therapy, and the risk of endometrial cancer

Previous studies of the association between cigarette smoking and endometrial cancer have yielded inconsistent results. There is some evidence that this discrepancy may be explained by differences in menopausal status between the groups of women studied. We addressed the issue of the effects of postmenopausal smoking on endometrial cancer risk using data from the Cancer and Steroid Hormone Study, a multicenter, population-based, case-control study of gynecologic cancers in the United States. We found that smoking after natural menopause is associated with a 70% reduced risk of endometrial cancer among estrogen users and a 50% reduced risk among nonusers of estrogen. These findings are consistent with previously proposed biologic effects of smoking on estrogen metabolism, which may have important clinical implications.

Vasectomies performed by private physicians, United States, 1980 to 1984

Using data from the National Disease and Therapeutic Index, we estimated that between 1980 and 1984, 1.9 X 10(6) U.S. men had vasectomies. Men between the ages of 30 and 39 years, and white men, were more likely than others to undergo the procedure. Further national data on this popular procedure are needed.

Characteristics of vasectomies performed in selected outpatient facilities in the United States, 1980

In 1981 the American Association of Gynecologic Laparoscopists and the Division of Reproductive Health, Centers for Disease Control, jointly conducted a study of vasectomies performed in outpatient facilities in 1980 in the United States. One hundred twenty-nine facilities that responded to either a mailed questionnaire or a telephone interview stated that vasectomies were performed there in 1980. The average cost was $273, with a range of $50-1,000. Facilities differed markedly in the use of anesthesia. Freestanding surgical centers reported the use of general anesthesia for 29% of the vasectomies. Other types of facilities were more likely to use local or regional anesthesia. Our data suggest areas for further research to improve the availability and safety of vasectomy.

Hysterectomy performed within 1 year after tubal sterilization

In the United States, approximately 650,000 women of reproductive age undergo tubal sterilization each year and some of these women later have hysterectomies. Little is known about risk factors for having hysterectomy after tubal sterilization. For examination of this issue, we analyzed data from the Collaborative Review of Sterilization, an ongoing multicenter prospective study designed to assess the safety and efficacy of female sterilization operations. In 1979 and 1980, 4002 women 15 to 44 years of age had interval tubal sterilization; of these women, 64 had hysterectomies within 15 months, which yielded a cumulative incidence of 1.6%. Women with a history of menstrual complaints, leiomyomata, ovarian cysts, or endometriosis before their tubal sterilization had an increased risk of hysterectomy, compared with women without such a history. However, 98% of women with a history of these conditions did not have a hysterectomy within 15 months after tubal sterilization. Further follow-up of these women should help to better delineate their long-term risks.