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Biomedical subjects

A C Klassen

Publications and source records attributed to A C Klassen.

At least 19 recordsLinked to original sources
PubMed2001

Comorbidity and survival of elderly head and neck carcinoma patients.

BACKGROUND: Alcohol and tobacco, the primary etiologic agents for head and neck carcinoma (HNCA), cause other chronic diseases and may contribute to the high prevalence of comorbid conditions and generally poor survival of persons with HNCA. METHODS: The authors explored the prognostic role of comorbidity in persons with HNCA using Health Care Finance Administration Medicare (HCFA) files linked with the appropriate files of the Surveillance, Epidemiology, and End Results (SEER) Program. The Charlson comorbidity index was applied to in-patient data from the HCFA files. The SEER data were used to ascertain survival and identify persons with HNCA diagnosed from 1985 to 1993 (n = 9386). RESULTS: In a proportional hazards regression model adjusted for age and historic stage at diagnosis, race, gender, marital status, socioeconomic status, histologic grade, anatomic site, treatment, and pre-1991 diagnosis, Charlson index scores of 0, 1, and 2+ had estimated relative hazards (RHs) with 95 confidence intervals (CIs) of 1.00, 1.33 (95% CI, 1.21-1.47), and 1.83 (95% CI, 1.64-2.05), respectively (P value for trend < 0.0001). The adjusted RH for a Charlson index score of 1 or more compared with 0, using stratified models, was found to be greater in whites (RH, 1.55; 95% CI, 1.43-1.67) than blacks (RH, 1.24; 95% CI, 0.96-1.60), local (RH, 1.72; 95% CI, 1.50-1.96) versus distant stage (RH, 1.25; 95% CI, 1.00-1.56), and age 65-74 years (RH, 1.53; 95% CI, 1.38-1.69) versus age 85+ years (RH, 1.42; 95% CI, 1.09-1.84). CONCLUSIONS: This study establishes comorbidity as a predictor of survival in an elderly HNCA population and lends support to the inclusion of comorbidity assessment in prognostic staging of patients with HNCA diagnosed after 65 years of age.

Aged↗
PubMed2001

The American Society of Anesthesiologists' class as a comorbidity index in a cohort of head and neck cancer surgical patients.

BACKGROUND: We assessed the American Society of Anesthesiologists' (ASA) class, as a measure of comorbidity in comparison to the commonly used Charlson index for prognostic ability in a HNCA population. METHODS: Proportional hazards methods were applied to head and neck cancer patients whose treatment included surgery by the Johns Hopkins Otolaryngology service (n = 388). RESULTS: The Charlson index and ASA class were modestly correlated (Spearman 0.36, p <.001). Compared with patients with ASA class 1 or 2, those with ASA class 3 or 4 had a two-fold elevated mortality rate (Relative Hazard (RH) = 2.00, 95% CI, 1.38-2.89). This association was stronger than observed for a Charlson index score of 1 or more compared with 0 (RH = 1.59, 95% CI, 1.17-2.17). Both the Charlson index and ASA class adjusted RHs displayed dose-response patterns (p value for trend <.001). CONCLUSIONS: Compared with the Charlson index, the ASA class had comparable if not greater prognostic ability for mortality in this elderly HNCA population.

Aged↗
PubMed1999

Community education for stroke awareness: An efficacy study.

BACKGROUND AND PURPOSE: This study examined the effectiveness of a slide/audio community education program aimed at increasing knowledge of stroke risk factors, stroke warning signs, and action needed when stroke warning signs occur. The program targets audiences at higher risk for stroke, especially individuals who are black or >50 years of age. METHODS: Subjects were 657 adults living in the community or in senior independent-living settings. The study examined the effectiveness of the program when presented alone and when accompanied by discussion (facilitation) led by a trained individual. Knowledge of stroke risk factors and warning signs was assessed using parallel pretests and posttests developed and validated specifically for the study. RESULTS: ANCOVA indicated that neither pretesting nor facilitation had a significant effect on posttest measures of knowledge. Paired t tests of groups receiving both the pretest and posttest demonstrated significant increase in knowledge (mean increase, 10.87%; P<0.001). ANCOVA indicated that these gains in knowledge were similar across subjects of different sex, race, age, and educational level. No significant differences could be ascribed to facilitation. CONCLUSIONS: The data indicate that the slide/audio program is effective in increasing knowledge of stroke risk factors, warning signs, and necessary action in subjects of varying ages, races, and education. Pretesting and facilitation did not significantly affect the short-term acquisition of information. The slide/audio program appears to offer a short, easily used educational experience for diverse communities, whether as a stand-alone program or with facilitated discussion.

Adult↗
PubMed1999

Organizational characteristics of solid-organ donor hospitals and nondonor hospitals.

CONTEXT: Efforts to increase organ donation include serious attempts in hospital settings, where unrealized donation potential exists. Research on hospital donation must include understanding organizational as well as patient-specific influences on the donation process. OBJECTIVE: To identify organizational characteristics that distinguish hospitals producing organ donations from those that do not, and to estimate the number of nondonor hospitals with donor potential. DESIGN: Data from the American Hospital Association's 1992 annual survey of hospitals were matched to Organ Procurement and Transplantation Network information from the United Network for Organ Sharing regarding the number of solid-organ donors in 1992. Hospitals with donation capability were identified, based on bed size and factors necessary to produce successful donor maintenance and organ recovery. Based on statistical analyses, organizational characteristics distinguishing donor hospitals from nondonor hospitals were identified. We also compared the number of donors and the number of donor hospitals in 1992 and 1996. SETTING: United States. RESULTS: Among all hospitals affiliated with the American Hospital Association (n = 5607), 1214 (22%) were identified as donor hospitals (> or = 1 donation in 1992). Of 2333 hospitals with procurement capability, 1268 (54%) produced no donors in 1992. Based on a multiple logistic regression model, donor hospitals differed from nondonor hospitals by hospital ownership, with municipally owned hospitals more likely and federally owned hospitals less likely to produce donation, compared with for-profit and not-for-profit hospitals. Other organizational characteristics associated with donor hospitals were level of trauma services, whether the hospital had a transplant surgery program or a hospital ethics committee, and whether it was located in the South Atlantic, Southwest Central, or Pacific regions of the United States. CONCLUSIONS: Among hospitals not currently producing organ donations, there is a sizable subgroup with donor potential. This area merits further attention.

American Hospital Association↗
PubMed1998

Factors influencing waiting time and successful receipt of cadaveric liver transplant in the United States. 1990 to 1992.

OBJECTIVES: Despite concern about access to liver transplantation, there has been no nationally based analysis of patients waiting for cadaveric liver transplant. Using data from the United Network for Organ Sharing Organ Procurement and Transplantation Network database waiting and recipient lists, we examined the influence of medical and non-medical factors on the length of time patients waited before transplant and whether they survived the wait. METHODS: The authors analyzed 7,422 entries to the waiting list from October 1, 1990 to December 31, 1992. Using Cox Proportional Hazard models, time to transplant was modelled by gender, nationality and ethnicity, age, blood type, medical status (critically ill versus non-critical), transplant number (first versus retransplant), United Network for Organ Sharing region of the country, and three measures of local demand and supply of organs. The risk of dying before being allocated an organ was compared with receiving an organ using multiple logistic regression models. RESULTS: In addition to differences by medical status, blood type, geographic region, and organ supply and demand, it was found that women, Hispanic-Americans, Asian-Americans, and children waited longer for transplant, whereas foreign nationals and repeat transplant patients waited fewer days. The risk of dying before transplant was greater for critically ill and repeat transplant patients, as well as for women, older patients, Asian-Americans, and African-Americans. Children were less likely to die, as were patients from certain blood groups and geographic regions. CONCLUSIONS: Results confirm known patterns of waiting list experience for liver transplant patients, but also identify factors previously unrecognized as influencing waiting time and outcome. Potential explanatory factors and areas for further inquiry are discussed.

Adolescent↗
PubMed1996

Who are the donors in organ donation? The family's perspective in mandated choice.

Evidence that families requested to permit organ donation refuse half the time has led to proposals for mandated choice. Under mandated choice, a person's donation wishes would be collected and retrieved at death, and requests to families would be avoided. There are both ethical and logistic problems with mandated choice. The view of the family should be respected in organ requests, even when patient wishes are known. Public sentiment against overriding family wishes could cause low rates of pro-donation registration. Caregivers have usually refused to take organs when families oppose donation. Logistic issues with mandated choice include the cost and complexity of maintaining a national database on donors and the enforcement of registration. No such database of adults currently exists, even for tax purposes. Two states that have mandated choice programs through departments of motor vehicles report relatively low number of pro-donation registrants compared with nondonors or undecided persons. Public education and voluntary donor identification hold more potential to increase donation.

Adult↗
PubMed1993

Cervical cancer screening in hospitals: the efficacy of legislation in Maryland.

OBJECTIVES: The purpose of the study was to examine the efficacy of a Maryland law requiring Pap testing to be offered during hospital admissions. "In-reach" strategies emphasize cancer screening within existing health care contacts (such as inpatient stays) rather than additional visits solely for screening. METHODS: Data from a 1986 telephone survey of Maryland women were used to examine the effect of hospitalization on self-reported Pap testing in a 3-year period. The effect of hospitalization on screening was examined by age and income to assess whether inpatient screening was more prevalent among certain subgroups of women. RESULTS: For the group as a whole, the odds of Pap screening did not vary with hospitalization. However, among women aged 45 to 54 years with annual household incomes over $20,000, hospitalized women were more likely than nonhospitalized women to report recent Pap tests. For low-income women aged 75 years and older, hospitalization actually decreased the likelihood of reporting Pap tests. CONCLUSIONS: Despite legislation, inpatient cervical cancer screening appears to mirror outpatient patterns, leaving elderly and low-income women unscreened. Methods for increasing inpatient Pap testing for underscreened women are discussed.

Aged↗
PubMed1989

Duration of relative protection of screening for cervical cancer.

The reduction in cervical cancer among women with at least one previous negative Pap smear can be assessed in terms of the time elapsed since the last smear was taken. One indicator of the utility of screening is the duration of relative protection, commonly calculated as the inverse of the disease odds ratio. Most investigations of the extent of relative protection provided by Pap testing have relied on data from centrally organized screening programs or case-control studies. For geographic areas without mass screening programs or tumor registries, reliance on subject recall of Pap tests is required. We conducted a case-control investigation of cervical cancer and interviewed 153 Maryland women with invasive disease and two control groups: 153 case-nominated controls and 392 randomly selected controls. The duration of relative protection of screening for disease was 4-6 years for both control groups [relative protection (RP) = 4.30, 95% confidence interval (CI) = 1.5-12.7 for neighborhood controls, RP = 3.63, 95% CI = 1.4-9.6 for random controls]. These findings held after adjusting for education, ever treated for a sexually transmitted disease, smoking, age at menarche and at first sexual intercourse, number of pregnancies, lifetime contraceptive use, and utilization of obstetrician-gynecologist services; the RPs increased upon adjustment. However, there was a decline in the RP with increased duration. Our findings are directly comparable to reports where smears have been verified, suggesting that self-reports of previous tests may be reliable as a method to evaluate the utility of screening.

Adult↗
PubMed1989

Variation in the duration of protection given by screening using the Pap test for cervical cancer.

The duration of protection offered by Pap screening for cervical cancer was examined using data on 101 cases of invasive cervical cancer and 396 controls from a Maryland case-control study. Receipt of a Pap test up to 4 years ago afforded significant protection, compared to women screened 11 or more years ago, or never screened. Smoking, intercourse before age 19, and a history of sexually transmitted disease were significant risk factors for cervical cancer; barrier contraception use was protective. Variation in protection from Pap screening was examined by age, race, age at first intercourse, barrier contraception use, and source of last Pap test (obstetrician-gynecologist vs other provider type). Results showed older women, women with earlier age of first intercourse, and non-users of barrier contraception received slightly less protection from Pap tests, while women who received their last Pap test from an obstetrician-gynecologist received significantly more protection than women who did not. Issues of quality of screening and follow-up are discussed in regard to these results.

Aged↗
PubMed1989

Practice changes in response to the malpractice litigation climate. Results of a Maryland physician survey.

Data from a 1987 survey of Maryland physicians in three specialties (internal medicine, family or general practice, and obstetrics-gynecology) were used to study the types of changes physicians have made in their practices during the last 2 years as a result of the current malpractice litigation climate. Overall, 51% reported making some type of practice change. The practice changes that physicians reported reflect both risk-reduction (e.g., increased use of tests) and risk-avoidance (e.g., cutting back high-risk patients) strategies, although risk-reduction actions were reported more frequently. Raising patient fees was also reported. Specialty predicts whether or not physicians make each type of change; in particular, obstetrician-gynecologists are more likely to report practice changes of all types. Prior litigation experience does not, in general, predict practice changes. The implications of the types of changes reported for access to care and costs of care were considered.

Data Collection↗
PubMed1988

Cervical cancer screening practices among older women: results from the Maryland Cervical Cancer Case-Control Study.

Considerable evidence shows a large proportion of older women have either never had a Pap test or have significant gaps in their history of cervical cancer screening. Differences in health care utilization patterns by age, cohort differences in use of medical subspecialities, and provider reluctance to perform cancer screening within the general medical care encounter have been suggested as reasons for underscreening. Our study conducted in 1985 documents prior health care utilization patterns of 153 cases of Maryland women with invasive cervical cancer compared with a matched control group. Analysis within three age groups showed that cases were significantly less likely to have ever had a Pap test or to receive regular Pap testing, primarily due to differences in medical care utilization patterns. Never having an obstetrician-gynecology visit, a recent (less than 3 years) internist visit, or not having any out-patient visit were significant risk factors. Other risks included older age at first Pap test, reporting not being told to have routine Pap tests, and not using contraceptives. In a multiple logistic regression analysis, recent out-patient visits and lifetime use of an obstetrician-gynecologist remained significant after adjusting for age interactions with recent Pap test history, underscoring the importance of medical care utilization patterns for screening of cancer of the uterine cervix among the elderly.

Adult↗
PubMed1988

Pap testing intervals. Specialty differences in physicians' recommendations in relation to women's pap testing behavior.

Using data from a survey of internists, family and general practitioners, and obstetricians and gynecologists, and of women in Maryland, this article examines congruence between physicians' recommendations and women's Papanicolaou (Pap) testing behavior. Both the specialty of the physicians and the age of the women are considered. The majority of all three physician specialties recommended annual Pap tests for all their patients. However, the internists and family or general practitioners were less likely to recommend annual Pap smears for their elderly patients than for their younger patients. Obstetrician-gynecologists were consistently more likely than the other specialties to recommend annual Pap tests, to send postcards to their patients reminding them to come in for Pap tests, and to view themselves as successful in inducing their patients to come in for routine Pap testing. Both the physicians and the women reported that elderly women were less likely than younger women to receive care from obstetrician-gynecologists. Women's reported Pap testing behavior indicated that they received Pap tests with far less frequency than the physicians recommended. Older age was related to less frequent Pap testing, while having a visit with an obstetrician-gynecologist was related to increased frequency. Findings indicate the need for education of physicians about methods of improving women's attendance for Pap testing and of women about the importance of routine Pap testing.

Age Factors↗
PubMed1987

The role of contraceptive use in cervical cancer: the Maryland Cervical Cancer Case-Control Study.

Recent evidence on the importance of sexual history and sexually transmissible agents in cervical cancer has been reported. Case-control studies have frequently demonstrated increased risk of cervical cancer for women using oral contraceptives, while laboratory results have shown that vaginal spermicides inactivate various sexually transmissible agents. To determine the role of contraceptive use in cervical cancer, 153 cases of Maryland women with invasive cervical cancer and age, race, and residence-matched controls were interviewed in 1985, focusing on sexual history, health care utilization patterns, screening history, contraceptive use, and smoking. Overall, lifetime use of contraceptives was protective of cervical cancer (odds ratio (OR) = 0.38, 95% confidence interval (CI) = 0.2-0.7). Use of oral contraceptives (OR = 0.48), diaphragm (OR = 0.29), and vaginal spermicides (OR = 0.28) were more frequent in controls than cases. After adjustment for behavioral factors (age at first intercourse, smoking, gaps in Papanicolaou smear testing, and obstetrician-gynecologist visits), use of vaginal spermicides remained significant (OR = 0.30), although use of oral contraceptives and barrier methods of contraception failed to remain significant. The effectiveness of vaginal spermicides in preventing cervical cancer may be due to their antiviral action.

Adult↗
PubMed1987

Utilization of obstetrician-gynecologists and prevention of cervical cancer.

In a case-control study, we examined health care utilization histories to determine whether Papanicolaou tests provided by an obstetrician-gynecologist, as opposed to other providers, are more protective of cervical cancer. Women with cervical cancer were less likely than matched controls to have had regular Papanicolaou test screening, to have received a Papanicolaou test within the last five years, or to have obtained a Papanicolaou test from an obstetrician-gynecologist. After controlling for traditional risk factors, we found that receiving any Papanicolaou tests within the last five years from an obstetrician-gynecologist was more protective than receiving Papanicolaou tests from other providers, although the difference did not attain statistical significance. Among both cases and controls, younger women and women who had used prescription contraceptives were more likely to have had a recent Papanicolaou test by an obstetrician-gynecologist. The results support the importance of regular Papanicolaou test screening among older women and suggest that the obstetrician-gynecologist helps prevent cervical cancer by providing continuity of screening services.

Adult↗
PubMed1984

Torticollis.

Explore the source record for details and available documents.

Humans↗
PubMed1984

Mechanisms of recovery from aphasia: evidence from serial xenon 133 cerebral blood flow studies.

In 21 patients who suffered aphasia resulting from left hemisphere ischemic infarction, the xenon 133 inhalation cerebral blood flow technique was used to measure cerebral blood flow within 3 months and 5 to 12 months after stroke. In addition to baseline measurements, cerebral blood flow measurements were also carried out while the patients were performing purposeful listening. In patients with incomplete recovery of comprehension and left posterior temporal-inferior parietal lesions, greater cerebral blood flow occurred with listening in the right inferior frontal region in the late studies than in the early studies. In patients with nearly complete recovery of comprehension and without left posterior temporal-inferior parietal lesions, early listening studies showed diffuse right hemisphere increases in cerebral blood flow. Later listening studies in this latter patient group showed greater cerebral blood flow in the left posterior temporal-inferior parietal region. The study provides evidence for participation of the right hemisphere in language comprehension in recovering aphasics, and for later return of function in left hemisphere regions that may have been functionally impaired early during recovery.

Adult↗
PubMed1982

Regional cerebral blood flow correlates of auditory processing.

To study the regional cerebral blood flow (rCBF) correlates of auditory processing, we performed rCBF measurements in young, normal right-handed volunteers engaged in listening tasks. Using the xenon Xe 133 inhalation technique, rCBF was measured in 11 regions in each hemisphere. Compared with a baseline condition, significant rCBF increases in the left posterior Sylvian regions were associated with both verbal phonologic processing and nonverbal acoustic processing. Verbal semantic processing was associated with unilateral increased rCBF in the posterior Sylvian region contralateral to the hand used for response signaling. Comparison of rCBF from homologous regions of the two hemispheres also confirmed a clear difference between the rhyme detection and meaning detection tasks, with the former strongly lateralized to the left hemisphere. Thus, changes in rCBF were related to the nature of the listening task.

Acoustic Stimulation↗