Partitioning linear trends in age-adjusted rates.

OBJECTIVE: Surveillance of chronic diseases includes monitoring trends in age-adjusted rates in the general population. Statistics that are calculated to describe and compare trends include the annual percent change and the percent change for a specified time period. However, it is also of interest to determine the contribution specific diseases make to an overall trend in order to better understand the impact of interventions and changes in the prevalence of risk factors. The objective here is to provide a method for partitioning a linear trend in age-adjusted rates into disease-specific components. METHODS: The method presented is based on linear regression. The decreasing trend in age-adjusted cancer mortality rates for the total United States during the period 1991-96 is analyzed to illustrate the method. RESULTS: Trends in mortality for cancers of the colon/rectum, breast, lung/bronchus, and prostate are found to be responsible for 75% of the decreasing trend in cancer mortality. CONCLUSIONS: It is possible to partition an overall trend in age-adjusted rates under the assumption that it and the trends for all mutually exclusive and exhaustive subgroups of interest are linear.

SEER data, corpus uteri cancer: treatment trends versus survival for FIGO stage II, 1988-1994.

OBJECTIVE: 1998 Surveillance, Epidemiology, and End Results (SEER) data estimate an 83.1% 5-year survival rate for corpus uteri adenocarcinoma FIGO stage II. The SEER data were evaluated to determine whether primary treatment differences using simple hysterectomy or radical hysterectomy, with or without radiation, altered disease survival. MATERIALS AND METHODS: SEER incidence data for FIGO II uterine corpus cancer of adenocarcinoma histology from 1988 to 1994 were stratified by hysterectomy type (simple versus radical) and whether radiation was given. Survival rates were calculated using a relative survival method and are expressed as percentages. Statistical analysis was done using a Z test. RESULTS: The 5-year cumulative survival rate for patients with stage II uterine corpus adenocarcinoma who received surgery alone as primary therapy was 84.36% with simple hysterectomy and 92.96% with radical hysterectomy (P<0.05). Survival for patients who received combination radiation and surgery as primary therapy was 82.77% with simple hysterectomy and 88.02% with radical hysterectomy (P<0.05). Pelvic and para-aortic nodes were negative. There was no significant survival difference for radiation versus no radiation in either surgical group. CONCLUSION: Radical hysterectomy is associated with better survival when compared to simple hysterectomy for FIGO II corpus uteri adenocarcinoma.

FIGO stage, histology, histologic grade, age and race as prognostic factors in determining survival for cancers of the female gynecological system: an analysis of 1973-87 SEER cases of cancers of the endometrium, cervix, ovary, vulva, and vagina.

The prognostic impact of FIGO stage, histology, histologic grade, age and race in survival for cancers of the female gynecological (cervix, endometrium, ovary, vulva, vagina) were examined using cases obtained from the National Cancer Institute's Surveillance, Epidemiology, and End Results (SEER) program that were diagnosed between 1973 and 1987. Utilizing Cox proportional hazards modeling and relative survival rates analysis of 17,119 cases of cervical cancer indicated that the International Federation of Gynecology and Obstetrics (FIGO) stage, histology, histological grade, lymph node status, and age at diagnosis were all independently prognostic. No evidence was found of survival differences between squamous cell carcinoma and adenocarcinoma. Younger women were not found to have a poorer prognosis, survival declined with increased age. Analysis of 41,120 cases of endometrial cancer indicated that FIGO stage, histology, histologic grade, lymph node status, age at diagnostic, and race were all prognostic factors. Clear cell adenocarcinoma, leiomyosarcoma, and mixed mullerian tumors were all found to have poorer prognosis. Analysis of 21,240 cases of ovarian cancer indicated that FIGO stage, histology, histologic grade, lymph node status, age at diagnosis, presence of ascites, and race were all prognostically significant. Analysis of 2,575 cases of vulvar cancer indicated that FIGO stage, histology, histologic grade, age, and race were all prognostically significant. Analysis of 916 cases of vaginal cancer indicated that FIGO stage, histologic grade, lymph node status, and age are all prognostically significant. Additional analysis of the data by combinations of independent prognostic factors indicates that the interaction of factors may be more predictive of outcome than any one factor separately.

1989 U.S. cesarean section rate steadies--VBAC rate rises to nearly one in five.

The 25 years of rising cesarean delivery rates in the United States may have finally run their course. In 1989 the rate of 23.8 cesareans per 100 deliveries was not significantly different from 24.7 in 1988, 24.4 in 1987, or 24.1 in 1986. The 1989 primary rate of 17.1 first cesareans per 100 women with no previous cesarean was also not significantly different from 17.5 for 1988, or 17.4 for 1987 and 1986. The percentage of vaginal births after cesarean section per 100 deliveries showed a remarkable rise between 1988 and 1989--from 12.6 percent in 1988 to 18.5 percent in 1989. Data are from the National Hospital Discharge Survey conducted by the National Center for Health Statistics, Centers for Disease Control.