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Biomedical subjects

R Warnecke

Publications and source records attributed to R Warnecke.

At least 19 recordsLinked to original sources
PubMed2005

Investigation of NOx precursor compounds and other combustion by-products in the primary combustion zone of a waste-incineration plant using on-line, real-time mass spectrometry and Fourier-transform infrared spectrometry (FTIR).

On-line analysis of trace and bulk gas compounds in the burning chamber of a waste-incineration plant has been performed, with high temporal resolution, by use of a variety of distinctly different measurement techniques. Time-of-flight mass spectrometry was performed with simultaneous use of three ionization techniques-resonance-enhanced multiphoton ionization (REMPI), single-photon ionization (SPI), and electron-impact ionization (EI). Chemical-ionization mass spectrometry (CIMS), Fourier-transform infrared spectrometry (FTIR), and electrochemical methods were also used. Sampling was conducted by means of a newly developed air-cooled stainless steel lance, to cope with the high temperatures and elevated particle concentrations at the sampling location. Nitrogen species were mainly nitrogen monoxide, ammonia, and hydrogen cyanide (HCN), with a small amount (approximately 0.3%) of aromatic nitrogen compounds. NO, NH(3), and HCN are the main contributors to the NO(x)-formation process in the postulated fuel-NO reaction scheme dominant at this location. The NO recycling process thereby plays a major role. Changes in plant operating conditions have a noticeable impact only when the air supply is varied. For example, reduction of oxygen leads to an increase in the HCN fraction of the total nitrogen content and a decrease in the NO fraction, and vice versa.

Incineration↗
PubMed2005

On-line analysis of gas-phase composition in the combustion chamber and particle emission characteristics during combustion of wood and waste in a small batch reactor.

The emission of particulate matter and gaseous compounds during combustion of wood and refuse-derived fuel in a small batch reactor is investigated by laser mass-spectrometric on-line measurement techniques for gas-phase analysis and simultaneous registration of physical aerosol properties (number size distribution). The gas-phase composition is addressed by a laser-based mass spectrometric method, namely, vacuum-UV single-photon ionization time-of-flight mass spectrometry (VUV-SPI-TOFMS). Particle-size distributions are measured with a scanning mobility particle sizer. Furthermore, a photoelectric aerosol sensor is applied for detection of particle-bound polycyclic aromatic hydrocarbons. The different phases of wood combustion are distinguishable by both the chemical profiles of gas-phase components (e.g., polycyclic aromatic hydrocarbons, PAH) and the particle-size distribution. Furthermore, short disturbances of the combustion process due to air supply shortages are investigated regarding their effect on particle-size distribution and gas-phase composition, respectively. It is shown that the combustion conditions strongly influence the particle-size distribution as well as on the emission of particle-bound polycyclic aromatic hydrocarbons.

Aerosols↗
PubMed2001

A randomized trial of a brief intervention to increase fruit and vegetable intake: a replication study among callers to the CIS.

BACKGROUND: Results are reported from a large randomized trial designed to increase fruit and vegetable consumption among callers to the National Cancer Institute's Cancer Information Service (CIS) (n = 1,717). METHODS: CIS callers assigned to the intervention group (n = 861) received a brief proactive educational intervention over the telephone at the end of usual service, with two follow-up mailouts. Key educational messages and print material derived from the NCI 5 A Day for Better Health program were provided to intervention participants. Participants were interviewed by telephone at 4 weeks (n = 1,307), 4 months (n = 1,180), and 12 months for follow-up (n = 1,016). RESULTS: Results obtained from a single-item measure of fruit and vegetable consumption indicate a significant intervention effect of 0.88 servings per day at 4 weeks follow-up (P < 0.001), 0.63 servings per day at 4 months follow-up (P < 0.001), and 0.43 servings per day at 12 months follow-up (P < 0.001). Using a 7-item food frequency measure, an intervention effect of 0.63 servings per day was obtained at 4 weeks follow-up (P < 0.001), compared with 0.39 servings per day at 4 months follow-up (P = 0.002) and 0.44 servings per day at 12 months follow-up (P = 0.002). A 24-h recall assessment included in the 4-month interviews also yielded a significant intervention effect of 0.67 servings per day (P = 0.015). The vast majority of callers (90%) endorsed the strategy of providing 5 A Day information proactively within the CIS. CONCLUSIONS: This brief educational intervention was associated with higher levels of self-reported fruit and vegetable intake at both short- and long-term follow-up. Additional research is recommended to test this or a similar intervention in diverse populations.

Adult↗
PubMed2001

Maintenance of a smoking cessation program in public health clinics beyond the experimental evaluation period.

OBJECTIVES: As phase 3 of a study to evaluate a smoking cessation program in public health practice, the authors assess the maintenance and impact of the It's Time smoking cessation program in seven public maternal and child health clinics in Chicago. METHODS: The authors interviewed 404 clinic patients in the study's baseline phase (prior to introduction of the It's Time intervention program), and 610 in the program maintenance phase (in the year after experimental evaluation had ended) to assess exposure to smoking cessation interventions offered at the clinic, and smoking cessation outcomes (quit, actions toward quitting, scores on action, motivation, readiness, and confidence scales). The authors controlled for clustering of smokers within clinics, smokers' characteristics prior to clinic visit, and type of clinic service. They compared outcomes by study group (control or intervention) to which each clinic had been assigned in the earlier experimental phase. RESULTS: Compared to baseline, smokers in the maintenance phase had greater exposure to posters, provider advice and booklet, and better outcomes on seven of eight smoking cessation measures, including quitting. These improvements were larger for clinics with prior experience implementing It's Time. CONCLUSION: Participation in the experimental evaluation of the It's Time program prepared and possibly motivated the clinics to continue the program. Continuing the program resulted in greater delivery of interventions and improved smoking cessation outcomes for smokers in the clinics.

Adult↗
PubMed2000

Minimal smoking cessation interventions in prenatal, family planning, and well-child public health clinics.

OBJECTIVES: This study assessed the prevalence and effectiveness of smoking cessation interventions for women of childbearing age in public health clinics. METHODS: Smokers in prenatal, family planning, and well-child services in 10 public health clinics (n = 1021) were interviewed 5 to 8 weeks after a medical visit to assess their exposure to smoking cessation interventions and smoking cessation outcomes. RESULTS: Depending on clinic service and intervention component (poster, video segment, provider advice, booklet), 16% to 63% of women reported exposure to an intervention component during their visit. Women in prenatal services received more interventions and had better outcomes than those in the other services. CONCLUSIONS: Exposure to more interventions increased readiness and motivation to quit and the number of actions taken toward quitting.

Adolescent↗
PubMed2000

The effect of a structured smoking cessation program, independent of exposure to existing interventions.

OBJECTIVES: This study assessed the effectiveness of a smoking cessation program for women in public health clinics, controlling for reported exposures to 4 common intervention components (provider advice, booklet, video segment, posters) among smokers in the control group. METHODS: After a baseline control period, 10 pair-matched clinics were randomly assigned to study groups. A total of 1042 smokers in the combined baseline and control groups and 454 smokers in the intervention group completed a preintervention questionnaire and a postintervention telephone interview 5 to 8 weeks later. Eight smoking outcomes, including quitting, were analyzed for the effect of reported exposure to intervention components, experimental program, and clinic service. RESULTS: Greater exposure to intervention components, being in the experimental program, and being seen in prenatal clinics independently improved smoking outcomes. CONCLUSIONS: The number of interventions reported by smokers in the control group ranged from none to 4 and varied across clinic services. The experimental program we tested produced better outcomes than the minimal smoking cessation interventions already existing in the control clinics, after we controlled for whether smokers were or were not exposed to these interventions.

Ambulatory Care Facilities↗
PubMed1999

Evaluation of a motivational smoking cessation intervention for women in public health clinics.

BACKGROUND: A multicomponent motivational smoking cessation intervention was evaluated in 33 prenatal, family planning, and pediatric services in 12 public health clinics. Clinic-based intervention components were implemented by clinic personnel as part of routine medical visits. METHODS: The evaluation design included pre- and postintervention measurements of multiple study outcomes in a baseline (all clinics prior to the start of the intervention) and an experimental period (matchedpair random assignment of clinics to intervention or control conditions). Subjects were 683 (baseline) and 1,064 (experimental) smokers with measurements of smoking outcomes at both times. Mixed-effects regressions analyzed individual outcomes clustered within clinics and services. RESULTS: Control and intervention clinics had similar outcomes in the baseline period. In the experiment, outcomes improved in the intervention but not in the control clinics. Compared to controls, smokers exposed to the intervention were more likely to have quit (14.5 versus 7.7%) or take actions toward quitting and had higher mean action, stage of readiness, and motivation to quit scores. These positive effects persisted when clustering within clinics and services was controlled. CONCLUSIONS: This intervention, implemented by clinic personnel as part of routine medical visits, was effective under these natural conditions across different types of clinic service.

Adult↗
PubMed1998

Sociopsychological correlates of motivation to quit smoking among low-SES African American women.

This article examines correlates of desire and plans to quit smoking among 248 young, low-socioeconomic status African American women, using variables derived from the health belief model (HBM) and the theory of reasoned action. Consistent with these theoretical models, stronger concern about the effect of smoking on one's health and having close others who want the smoker to quit increased motivation to quit smoking. However, motivation was not associated with specific HBM components regarding lung cancer. Heavier smoking and stronger perceptions regarding the functional utility of smoking decreased motivation to quit, but not as much as expected in this study population. Consistent with a process of change approach to smoking cessation, the factors that moved smokers from not planning to planning to ever quit were different from factors associated with further motivation level among the smokers who did plan to ever quit.

Adult↗
PubMed1997

Method effects in survey and focus group findings: understanding smoking cessation in low-SES African American women.

The same pool of African American women participated in a survey and in focus groups on motivation to quit smoking. Findings from the two studies were compared to explore potential method effects. Consistent with each method's basic purposes, the survey identified variation in study variables based on accepted theory and association patterns among such variables. The focus groups discovered themes and images salient to the participants and highlighted the situational contexts that gave meaning to smoking and smoking cessation. Survey method limitations included poor sensitivity to topic salience and contextual meanings and a deductive mode that channeled interpretation of results within the boundaries predefined by the study's theoretical framework. Focus group method limitations included an overfocus on the most dramatic and uncommon evidence and lack of systematic ways to identify explanations that may underlie the participants' overt expressions. Together, the multiple findings complemented and explained each other.

Adolescent↗
PubMed1994

Accrual of patients to randomized clinical trials. Factors affecting cancer prevention and control research.

Clinical judgment is increasingly being challenged by the need for randomized clinical trials. The 1987 National Cancer Institute mandate--that the Community Clinical Oncology Program (CCOP) accrue patients to cancer control protocols--provided an opportunity to examine the factors that affect accrual performance. An analysis of 52 CCOPs and their research bases participating in the program found that the availability of protocols, involvement with research base activities, a demonstrated link to community physicians (particularly those physicians, such as surgeons, who had access to patients), and the use of personal contacts to inform non-CCOP physicians about CCOP activities were important facilitating factors for accruing patients to cancer prevention and control trials.

Humans↗
PubMed1993

Assuring access to state-of-the-art care for U.S. minority populations: the first 2 years of the Minority-Based Community Clinical Oncology Program.

BACKGROUND: The Minority-Based Community Clinical Oncology Program (MBCCOP) was initiated in September 1990 to expand the National Cancer Institute's (NCI's) clinical trials network to minority populations. Institutions, organizations, and/or physician groups that had more than 50% of new cancer patients from minority groups were eligible to participate. There has been no previous evaluation of the MBCCOP. PURPOSE: This study was designed to describe the early implementation of the MBCCOP and identify the challenges that have emerged in developing a network aimed at increasing the participation of minority populations in clinical trials. METHODS: Data were taken from primary and secondary sources, including site visits and patient log data, that described performance of 12 MBCCOP centers initially funded in September 1990. Accrual was measured by the number of credits earned per MBCCOP for patients enrolled in research protocols for cancer treatment or for prevention and control, which includes activities such as early detection, pain control, and rehabilitation. These accrual credits, assigned by the NCI, were based on the complexity of the protocol and the amount of resources expected to be required for accrual of patients by the MBCCOP. RESULTS: Data for the first 2 years of the MBCCOP showed that 344 patients were accrued to trials of treatment protocols from June 1, 1990, to May 31, 1991, and this number increased to 470 during the second accrual year, June 1, 1991, to May 31, 1992. Similarly, accrual of patients to cancer prevention and control studies increased from 256 in 1990-1991 to 423 in 1991-1992. More than 70% of the MBCCOP patients entered in studies were from minority populations. The proportion of eligible MBCCOP patients entered into treatment protocols was identical with that experienced by the initial Community Clinical Oncology Program (CCOP). Results also demonstrated that MBCCOP centers operate in an environment characterized by socio-economic decline and limited resources, both having substantial effects on the implementation of clinical trials among minorities. While minority patients are willing to participate in clinical trials, there are profound barriers involving language, logistics, and the appropriateness of available protocols. Participating physicians, nurses, and support personnel report a high level of agreement with program goals and have developed unique approaches to meeting the challenges faced in the implementation of this program. CONCLUSIONS: The MBCCOPs have demonstrated their ability to participate in clinical trials. Evaluation reveals, however, that they are emerging organizations influenced by factors endemic to the community they serve and their own structure. The MBCCOPs are confronting substantial challenges, yet they provide an important link to the overall NCI clinical trials network.

Aged↗
PubMed1993

Predicting the performance of a strategic alliance: an analysis of the Community Clinical Oncology Program.

OBJECTIVE: This study is designed to examine the effects of environment and structure of the Community Clinical Oncology Program (CCOP) on performance as measured by patient accrual to National Cancer Institute (NCI)-approved treatment protocols. DATA SOURCES/STUDY SETTING: Data and analysis are part of a larger evaluation of the NCI Community Clinical Oncology Program during its second funding cycle, June 1987-May 1990. Data, taken from primary and secondary sources, included a survey of selected informants in CCOPs and research bases, CCOP grant applications, CCOP annual progress reports, and site visits to a subsample of CCOPs (N = 20) and research bases (N = 5). Accrual data were obtained from NCI records. STUDY DESIGN: Analysis involved three complementary sets of factors: the local health care resources environment available to the CCOP, the larger policy environment as reflected by the relationship of the CCOP to selected research bases and the NCI, and the operational structure of the CCOP itself. A hierarchical model examined the separate and cumulative effects of local and policy environment and structure on performance. PRINCIPAL FINDINGS: Other things equal, the primary predictors of treatment accrual were: (1) the larger policy environment, as measured by the attendance of nurses at research base meetings; and (2) operational structure, as measured by the number and character of components within participating CCOPs and the number of hours per week worked by data managers. These factors explained 73 percent of the total variance in accrual performance. CONCLUSIONS: Findings suggest criteria for selecting the types of organizations to participate in the alliance, as well as for establishing guidelines for managing such alliances. A future challenge is to determine the extent to which factors predicting accrual to cancer treatment clinical trials are equally important as predictors of accrual to cancer prevention and control trials.

Clinical Protocols↗
PubMed1992

Smoking-related behavior, beliefs, and social environment of young black women in subsidized public housing in Chicago.

Survey data indicate that young Black female smokers living in public housing are heavier smokers and have weaker motivation to quit, health beliefs and social environment less conducive to cessation, and less knowledge of where to get help to quit than other young Black female smokers in metropolitan Chicago. Compared with White women, the latter, other Black women smoke fewer cigarettes daily and have a stronger desire to quit and more concern about health reasons for quitting, but have a weaker belief in the risk of lung cancer from smoking, greater concern about quitting difficulties, and less knowledge of where to get help to quit. Low education, not race, is associated with higher smoking prevalence and less social pressure to quit or support for quitting.

Adolescent↗
PubMed1991

Cancer control and the older person. Prevention and detection in older persons.

Older persons are appropriate targets for a range of prevention and early detection interventions, however, greater emphasis should be given to structuring the delivery of prevention and detection services to the special needs of this population. This may require research and program development to reach older persons in the most effective and cost-effective manner. The American Cancer Society and other program efforts must accommodate the heterogeneity and special needs of segments of the older population. Racial and cultural minorities, impoverished persons, the cognitively impaired, and the physically impaired are four groups requiring special attention. Early detection guidelines specific to older persons should be developed.

Aged↗
PubMed1990

The role of thematic evaluation in program assessment: the case of the Community Clinical Oncology Program.

The evaluation of programs with multiple, and potentially conflicting, goals requires the integration of measures of goal achievement that often are not easily combined. One approach is the development of analytical themes which span the various goals of a particular program. The themes provide a mechanism by which the policy concerns of individuals with varying perspectives can be integrated into the evaluation framework. As well, the themes allow for flexibility in the development of new analysis as the program matures and environments change. This paper describes the application of the thematic approach to the evaluation of a complex, community-oriented cancer research program.

Clinical Trials as Topic↗
PubMed1990

Results of an intervention to improve compliance with referrals for evaluation of suspected malignancies at neighborhood public health centers.

A study was conducted at Neighborhood Health Centers to evaluate procedures to improve compliance with referrals of patient at risk for cancer. Intervention consisted of a standardized communication from the exit nurse, a patient form to be returned after compliance, and one written and one telephone reminder as needed. Compliance was 68.2 percent in a control group and 89.0 percent among patients who received the experimental intervention, a significant increase of 20.8 percent (95% CI: 12.5, 29.1).

Adult↗
PubMed1989

Evaluating organizational design to assure technology transfer: the case of the Community Clinical Oncology Program.

Current theories of organizational performance are used to guide researchers at the Health Services Research Center of the University of North Carolina at Chapel Hill and the University of Illinois Survey Research Laboratory in the evaluation of the National Cancer Institute's Community Clinical Oncology Program (CCOP) and to derive policy options to enhance program operations. CCOP represents an innovative mechanism designed to improve the accrual of patients to phase III clinical trials, involve community-based oncologists in clinical research, and potentially to disseminate new information on the state-of-the-art cancer treatment to areas distant from cancer centers and research-oriented medical centers. Examined in this evaluation of the second phase of the CCOP are the ability of the 52 currently funded CCOPs and 17 research bases to accrue patients to cancer treatment and cancer control research protocols, their influence on the patterns of practice for cancer treatment in CCOP communities, and their influence on cancer control awareness and activity among primary care physicians. The evaluation applies selected organizational perspectives to describe the intraorganizational and interorganizational characteristics of the CCOPs, research bases, and the Institute that may affect the performance of the CCOP. This organizational approach relates the accrual and influence of the CCOP to controllable aspects of the program's design and management strategies that can be changed through policies directed by the National Cancer Institute. These policies include the criteria used to select CCOPs, the role of research bases in the development and implementation of treatment and cancer control research protocols, and the use of accrual credits.

Academies and Institutes↗