Biomedical subjects

John S Preisser

Publications and source records attributed to John S Preisser.

At least 19 recordsLinked to original sources

PubMed2007

Dementia care mapping as a research tool.

INTRODUCTION: Dementia Care Mapping (DCM) was originally developed as a clinical tool but has attracted interest as a potential observational measure of quality of life (QOL) and well-being of long-term care residents with dementia. DCM coding involves continuous observation over a 6-h period, with observers recording a Behavior Category Code (BCC, a recording of activity/interaction) and a Well/Ill Being (WIB) score at 5 min intervals. METHOD: Descriptive data from several different research teams on the distribution and psychometric properties of DCM data were compiled and summarized. RESULTS: Issues and problems identified include: complex scoring algorithms, inter-rater reliability of the BCCs, limited variability of WIB values, associations between resident characteristics and DCM assessments, rater time burden, and comparability of results across study settings. CONCLUSIONS: Despite the identified limitations, DCM has promise as a research measure, as it may come closer to rating QOL from the perspective of persons with dementia than other available measures. Its utility will depend on the manner in which it is applied and an appreciation of the measure's strength and limitations. Possible changes that might improve the reliability, validity, and practicality of DCM as a research tool include coding the predominant event (rather than the 'best' event), shortening the observation period, and adding '0' as a neutral WIB coding option.

Activities of Daily Living↗

PubMed2006

Effects of solubilizing surfactants and loading of antiviral, antimicrobial, and antifungal drugs on their release rates from ethylene vinyl acetate copolymer.

OBJECTIVES: This study investigates the effects of surfactants and drug loading on the drug release rate from ethylene vinyl acetate (EVA) copolymer. The release rate of nystatin from EVA was studied with addition of non-ionic surfactants Tween 60 and Cremophor RH 40. In addition, the effect of increasing drug load on the release rates of nystatin, chlorhexidine diacetate and acyclovir is also presented. METHOD: Polymer casting solutions were prepared by stirring EVA copolymer and nystatin (2.5wt.%) in dichloromethane. Nystatin and surfactants were added in ratios of (1:1), (1:2) and (1:3). Drug loading was studied with 2.5, 5.0, 7.5, and 10.0wt.% proportions of nystatin, chlorhexidine diacetate and acyclovir incorporated into a separate polymer. Three drug loaded polymer square films (3cmx3cmx0.08cm) were cut from dry films to follow the kinetics of drug release at 37 degrees C. Ten milliliters of either distilled water or PBS was used as the extracting medium that was replaced daily. PBS was used for nystatin release with addition of surfactants and water was used for the study on drug loading and surfactant release. The rate of drug release was measured by UV-spectrophotometer. The amount of surfactant released was determined by HPLC. RESULTS: The release of nystatin was low in PBS and its release rate increased with the addition of surfactants. Also, increasing surfactant concentrations resulted in increased drug release rates. The release rates of chlorhexidine diacetate (p<0.0001), acyclovir (p<0.0003) and nystatin (p<0.0017) linearly increased with increasing drug loads. The amount of surfactants released was above the CMC. SIGNIFICANCE: This study demonstrates that the three therapeutic agents show a sustained rate of drug release from EVA copolymer over extended periods of time. Nystatin release in PBS is low owing to its poor solubility. Its release rate is enhanced by addition of surfactants and increasing the drug load as well.

Acyclovir↗

PubMed2006

Three months in the symptom life of a teenage girl undergoing treatment for cancer.

The purpose of this case study was to examine the daily symptom experience of a teenage girl, Abby, undergoing treatment for cancer. Quantitative and qualitative data collection and analysis techniques were used to ascertain patterns in daily experiences of pain, nausea, vomiting, retching, stress, sleep alterations, and anxiety. A time-series analysis focused on change and variability in patterns of symptom data. A key finding was that the predictability evident in Abby's symptom patterns were in direct contrast to her perception that there was no predictability or pattern to her symptoms. Her perceived lack of control over her symptoms generated worry, anxiety, and depression and led Abby to question whether she could continue with the treatment. Abby represented a case of "fighting the treatment," as opposed to "fighting the cancer," and it is the difference between these responses that may explain children's overall ability to tolerate intensive chemotherapy.

Adolescent↗

PubMed2006

Reducing the bias of probing depth and attachment level estimates using random partial-mouth recording.

OBJECTIVES: To evaluate the bias and precision of probing depth (PD) and clinical attachment level (CAL) estimates of random and fixed partial examination methods compared with full-mouth examinations. METHODS: PD and CAL were calculated on six sites for up to 28 teeth (considered to be the gold standard with no bias) and three fixed-site selection methods (FSSMs) that resulted in a partial examination of sites: the Ramfjord method, and the NIDCR methods used in NHANES I, and NHANES 2000. Finally, seven random-site selection methods (RSSMs) were created by sampling the following number of sites: 84, 42, 36, 28, 20, 15, 10 and 6. To compare bias and precision of the methods we calculated percent relative bias and relative error. RESULTS: Estimates of means, standard deviations (SD), relative bias and relative error for RSSMs were almost identical to the full-mouth examination, but SDs increase slightly when fewer than 28 sites were sampled and relative bias and error increase for methods sampling fewer than 20 sites. The FSSMs had very low relative error, but much higher relative bias indicating underestimation. The FSSM with the smallest bias and error was the Ramfjord method, but the Random 36 method had less bias and less relative error. The NHANES 2000 method was the FSSM with the lowest bias and relative error for estimates of Extent Scores (percent of sites > or =3, 4, 5, or 5 mm PD or CAL) but random methods sampling fewer sites performed just as well. Both FSSMs and RSSMs underestimated prevalence, especially prevalence of less frequently occurring conditions, but most RSSMs were less likely to underestimate prevalence than the FSSMs. CONCLUSION: The promise of reducing bias and increasing precision of the estimates support the continued development and examination of RSSMs.

Aged↗

PubMed2006

Multilevel analysis of group-randomized trials with binary outcomes.

OBJECTIVES: Many dental studies have assessed the effectiveness of community- or group-based interventions such as community water fluoridation. These cluster trials, of which group-randomized trials (GRTs) are one type, have design and analysis considerations not found in studies with randomization of treatments to individuals (randomized controlled trials, RCTs). The purpose of this paper is to review analytic methods used for the analysis of binary outcomes from cluster trials and to illustrate these concepts and analytical methods using a school-based GRT. METHODS: We examine characteristics of GRTs including intra-class correlation (ICC), their most distinctive feature, and review analytical methods for GRTs including group-level analysis, adjusted chi-square test and multivariable analysis (mixed effect models and generalized estimating equations) for correlated binary data. We consider two- and three-level modeling of data from a cross-sectional cluster design. We apply the concepts reviewed using a GRT designed to determine the effect of incentives on response rates in a school-based dental study. We compare the results of analyses using methods for correlated binary data with those from traditional methods that do not account for ICC. RESULTS: Application of traditional analytic methods to the dental GRT used as an example for this paper led to a substantial overstatement of the effectiveness of the intervention. CONCLUSIONS: Ignoring the ICC among members of the same group in the analysis of public health intervention studies can lead to erroneous conclusions where groups are the unit of assignment. Special consideration is needed in the analysis of data from these cluster trials. Randomization of treatments to groups also should receive more consideration in the design of cluster trials in dental public health.

Algorithms↗

PubMed2005

A suite of methods for representing activity space in a healthcare accessibility study.

BACKGROUND: "Activity space" has been used to examine how people's habitual movements interact with their environment, and can be used to examine accessibility to healthcare opportunities. Traditionally, the standard deviational ellipse (SDE), a Euclidean measure, has been used to represent activity space. We describe the construction and application of the SDE at one and two standard deviations, and three additional network-based measures of activity space using common tools in GIS: the road network buffer (RNB), the 30-minute standard travel time polygon (STT), and the relative travel time polygon (RTT). We compare the theoretical and methodological assumptions of each measure, and evaluate the measures by examining access to primary care services, using data from western North Carolina. RESULTS: Individual accessibility is defined as the availability of healthcare opportunities within that individual's activity space. Access is influenced by the shape and area of an individual's activity space, the spatial distribution of opportunities, and by the spatial structures that constrain and direct movement through space; the shape and area of the activity space is partly a product of how it is conceptualized and measured. Network-derived measures improve upon the SDE by incorporating the spatial structures (roads) that channel movement. The area of the STT is primarily influenced by the location of a respondent's residence within the road network hierarchy, with residents living near primary roads having the largest activity spaces. The RNB was most descriptive of actual opportunities and can be used to examine bypassing. The area of the RTT had the strongest correlation with a healthcare destination being located inside the activity space. CONCLUSION: The availability of geospatial technologies and data create multiple options for representing and operationalizing the construct of activity space. Each approach has its strengths and limitations, and presents a different view of accessibility. While the choice of method ultimately lies in the research question, interpretation of results must consider the interrelated issues of method, representation, and application. Triangulation aids this interpretation and provides a more complete and nuanced understanding of accessibility.

Journal Article↗

PubMed2005

Accessing a new medication in Germany: a novel approach to assess a health insurance-related barrier.

PURPOSE: Knowledge of the existence, position, and magnitude of barriers to equitable healthcare is an important consideration in shaping healthcare policies. METHODS: The authors developed a novel three-dimensional person-time-related hurdle model and followed a cohort of 7358 statutorily (SHI) and 457 privately health insured (PHI) patients with migraine headaches at 377 primary-care practices (MediPlus, IMS Health) in the second to fourth year of the HealthCare Structural Reform Act in Germany. RESULTS: For SHI compared with PHI migraine patients, there was a hurdle to receiving sumatriptan at all (2.4-fold lower hazard, 95% confidence interval, 1.8-3.2). Among patients who received sumatriptan, frequency and intensity of use differed only minimally between SHI and PHI patients. CONCLUSIONS: These findings have implications for healthcare researchers and healthcare policies. The framework extends traditional hurdle models and can serve as a model for quantifying barriers to receipt of services under different funding policies.

Adolescent↗

PubMed2005

Chronic maternal and fetal Porphyromonas gingivalis exposure during pregnancy in rabbits.

OBJECTIVE: This study was undertaken to develop a rabbit model of maternal exposure to Porphyromonas gingivalis and determine whether fetal or placental exposure occurs. STUDY DESIGN: Subcutaneous steel chambers were implanted in 8 New Zealand White female rabbits. On day 7 of pregnancy, 4 rabbits were inoculated through the chamber with 5 x 10 8 CFU/mL live P gingivalis , and 4 rabbits with broth (controls) and sacrificed at term. Polymerase chain reaction was used to detect P gingivalis in maternal and fetal liver and placenta. Fisher exact test was used to compare P gingivalis detection between groups. RESULTS: Among exposed does, P gingivalis was detected in 33% of the maternal livers, 49% of placentas, and 34% fetal livers compared with none from controls ( P < .001). CONCLUSION: Chronic maternal exposure to P gingivalis results in systemic dissemination, transplacental passage, and fetal exposure. This model may be useful to study placental and fetal effects of this oral pathogen and to study microbial dissemination across the placenta.

Animals↗

PubMed2005

Insulin-like growth factor and interleukin-1beta levels and subsequent fetal size in response to chronic Porphyromonas gingivalis exposure in the pregnant rabbit.

OBJECTIVE: The purpose of this study was to describe maternal insulin-like growth factor, interleukin-1beta, and fetal size in a rabbit model of Porphyromonas gingivalis exposure. STUDY DESIGN: With the use of a previously described model, 8 New Zealand White rabbits were exposed to either P gingivalis or media during pregnancy and killed at term. Kit and placenta weight were compared between groups. Doe serum insulin-like growth factor system protein and interleukin-1beta levels were compared by analysis of variance for repeated measures; a probability value of <.05 was considered to be significant. RESULTS: No significant differences in kit and placental weights between exposed and unexposed groups were observed. Insulin-like growth factor system proteins increased significantly as pregnancy progressed, but there were no significant differences in insulin-like growth factor system proteins or interleukin-1beta between exposed and unexposed does. CONCLUSION: Chronic P gingivalis exposure does not disrupt insulin-like growth factor system proteins or systemic inflammation and does not impair fetal growth in the pregnant rabbit. Gestational age changes in doe insulin-like growth factor system proteins occur, and the timing of exposure to oral pathogens may influence fetal growth.

Animals↗

PubMed2005

Children's health and workers' productivity: an examination of family interference with work in rural America.

This article examines the association of children's health with their parents' performance in the workplace using data from a random survey sample of adults living in rural western North Carolina (N=206). Guided by the effort-recovery model, the authors hypothesized that parents whose children are more ill have poorer performance in the workplace because their parenting requires greater effort and they have less opportunity for physical and psychological recovery. Child health was unassociated with parents cutting back at work because of physical health. Poorer child health was associated with parents cutting back at work because of emotional health, and a portion of this association, as hypothesized, was explained by more limited opportunities for parental recovery. There was no evidence suggesting that associations differed by parental gender.

Adult↗

PubMed2005

Factors associated with nursing assistant quality-of-life ratings for residents with dementia in long-term care facilities.

PURPOSE: We identify resident, nursing assistant, and facility factors associated with nursing assistant quality-of-life ratings for residents with dementia in long-term care. DESIGN AND METHODS: We used a cross-sectional survey of 143 nursing assistants providing care to 335 residents in 38 residential care/assisted living (RC/AL) facilities and nursing homes in four states. We assessed resident quality of life by using the Quality of Life-Alzheimer's Disease Scale (QOL-AD). RESULTS: Scores on the quality-of-life scale were most strongly associated with resident clinical conditions, including severity of cognitive and functional impairments, depression, and behavioral symptoms of dementia. There was also an independent positive association between nursing assistants' ratings of resident quality of life and their own attitudes regarding dementia-person-centered care as well as training. However, the results of hierarchical linear modeling suggest that some sources of nursing assistant variability in quality-of-life ratings remain unidentified. IMPLICATIONS: Quality-of-life ratings by nursing assistants may be influenced by their attitudes about dementia and their confidence in addressing residents' fundamental care needs.

Adult↗

PubMed2005

Dementia care and quality of life in assisted living and nursing homes.

PURPOSE: There are few empirical studies relating components of long-term care to quality of life for residents with dementia. This study relates elements of dementia care in residential care/assisted living (RC/AL) facilities and nursing homes to resident quality of life and considers the guidance this information provides for practice and policy. DESIGN AND METHODS: We used a variety of report and observational measures of the structure and process of care and 11 standardized measures of quality of life to evaluate the care for and quality of life of 421 residents with dementia in 35 RC/AL facilities and 10 nursing homes in four states. Data were collected cross sectionally on-site, and we conducted a 6-month follow-up by telephone. RESULTS: Change in quality of life was better in facilities that used a specialized worker approach, trained more staff in more domains central to dementia care, and encouraged activity participation. Residents perceived their quality of life as better when staff was more involved in care planning and when staff attitudes were more favorable. Better resident-staff communication was related to higher quality of life as observed and reported by care providers. Also, more stable resident-staff assignment was related to care providers' lower quality-of-life ratings. IMPLICATIONS: Improvement in resident quality of life may be achieved by improved training and deployment of staff.

Aged, 80 and over↗

PubMed2005

Evaluating the quality of life of long-term care residents with dementia.

PURPOSE: This study's purpose was to better understand existing measures of quality of life in dementia residents of long-term care facilities. DESIGN AND METHODS: We gathered data from 421 residents in 45 facilities. Analyses determined the psychometric properties of each measure, estimated the relationship between measures, and identified the extent to which resident characteristics predicted scores. RESULTS: Most instruments had good to excellent dispersion and interrater reliability, and most scales had good to excellent internal consistency. Proxy measures tended to correlate best with each other, less well with observational measures, and least well with resident measures. Resident cognition and activities of daily living (ADLs) function were associated with most quality-of-life measures but predicted no more than a quarter of the observed variance in any measure. IMPLICATIONS: Various measures and sources of data provide different perspectives on quality of life. No "gold standard" exists; so a combination of methods and sources is likely to provide the most complete picture of quality of life.

Aged↗

PubMed2005

Characteristics associated with mobility limitation in long-term care residents with dementia.

This article describes the prevalence, assessment, and treatment of, as well as characteristics associated with, mobility limitation in 343 residents with dementia in 45 assisted living facilities and nursing homes. Overall, 89% of residents had some degree of mobility limitation. Mobility limitation was associated with fewer behavioral symptoms, low fluid intake, professional assessment, and professional and informal treatment.

Assisted Living Facilities↗

PubMed2005

Families filling the gap: comparing family involvement for assisted living and nursing home residents with dementia.

PURPOSE: The purpose of this study was to compare the sociodemographics, self-rated health, and involvement levels of family caregivers of residents with dementia in residential care/assisted living (RC/AL) versus nursing home settings. DESIGN AND METHODS: We conducted telephone interviews with the family caregivers most involved with 353 residents of 34 residential care and 10 nursing home facilities. We measured involvement by caregiver self-report of monthly out-of-pocket spending, involvement and burden ratings, and the frequency of engaging in eight specific care activities. Open-ended questions elicited areas in which caregivers preferred different involvement and ways the facility could facilitate involvement. RESULTS: Nursing home caregivers rated their health poorer than RC/AL caregivers, but there were no sociodemographic differences between the two. RC/AL caregivers rated both their perception of involvement and burden higher and engaged more frequently in monitoring the resident's health, well-being, and finances than did nursing home caregivers, although the reported time spent per week on care did not differ. IMPLICATIONS: RC/AL and nursing home caregivers to residents with dementia may tailor their care to fit the needs of the resident and setting. Results are discussed in relation to the Congruence Model of Person-Environment Fit.

Adult↗

PubMed2005

Attitudes, stress, and satisfaction of staff who care for residents with dementia.

PURPOSE: Considering the increasing proportion of residents in long-term care who have dementia, and the important influence that direct care providers have on resident quality of life, this study explores the dementia-related attitudes of residential care/assisted living (RC/AL) and nursing home staff, as well as their work stress and satisfaction. DESIGN AND METHODS: Data were derived from interviews with 154 direct care providers from 31 RC/AL facilities and 10 nursing homes who participated in the Collaborative Studies of Long-Term Care. RESULTS: Stress was more often reported by care providers who had been working for 1 to 2 years (compared with longer); in addition, those who had been working for 1 to 2 years were more likely to espouse hopeful or person-centered attitudes than those who had been working for a longer period of time. Also, a person-centered attitude related to satisfaction, and perceived competence in providing dementia care was consistently associated with dementia-sensitive attitudes and job satisfaction. IMPLICATIONS: Attending to the welfare and ongoing training of workers who have demonstrated job commitment may lessen their tendency to become jaded over time or seek job opportunities elsewhere. Further, the attitudes the staff hold related to dementia and the training they receive to provide dementia care are important for their own well-being.

Adult↗

PubMed2005

The effects of geography and spatial behavior on health care utilization among the residents of a rural region.

OBJECTIVE: This analysis determines the importance of geography and spatial behavior as predisposing and enabling factors in rural health care utilization, controlling for demographic, social, cultural, and health status factors. DATA SOURCES: A survey of 1,059 adults in 12 rural Appalachian North Carolina counties. STUDY DESIGN: This cross-sectional study used a three-stage sampling design stratified by county and ethnicity. Preliminary analysis of health services utilization compared weighted proportions of number of health care visits in the previous 12 months for regular check-up care, chronic care, and acute care across geographic, sociodemographic, cultural, and health variables. Multivariable logistic models identified independent correlates of health services utilization. DATA COLLECTION METHODS: Respondents answered standard survey questions. They located places in which they engaged health related and normal day-to-day activities; these data were entered into a geographic information system for analysis. PRINCIPAL FINDINGS: Several geographic and spatial behavior factors, including having a driver's license, use of provided rides, and distance for regular care, were significantly related to health care utilization for regular check-up and chronic care in the bivariate analysis. In the multivariate model, having a driver's license and distance for regular care remained significant, as did several predisposing (age, gender, ethnicity), enabling (household income), and need (physical and mental health measures, number of conditions). Geographic measures, as predisposing and enabling factors, were related to regular check-up and chronic care, but not to acute care visits. CONCLUSIONS: These results show the importance of geographic and spatial behavior factors in rural health care utilization. They also indicate continuing inequity in rural health care utilization that must be addressed in public policy.

Adult↗

PubMed2005

Access to transportation and health care utilization in a rural region.

CONTEXT: Access to transportation to transverse the large distances between residences and health services in rural settings is a necessity. However, little research has examined directly access to transportation in analyses of rural health care utilization. PURPOSE: This analysis addresses the association of transportation and health care utilization in a rural region. METHODS: Using survey data from a sample of 1,059 households located in 12 western North Carolina counties, this analysis tests the relationship of different transportation measures to health care utilization while adjusting for the effects of personal characteristics, health characteristics, and distance. FINDINGS: Those who had a driver's license had 2.29 times more health care visits for chronic care and 1.92 times more visits for regular checkup care than those who did not. Respondents who had family or friends who could provide transportation had 1.58 times more visits for chronic care than those who did not. While not significant in the multivariate analysis, the small number who used public transportation had 4 more chronic care visits per year than those who did not. Age and lower health status were also associated with increased health care visits. The transportation variables that were significantly associated with health care visits suggest that the underlying conceptual frameworks, the Health Behavior Model and Hagerstrand's time geography, are useful for understanding transportation behavior. CONCLUSIONS: Further research must address the transportation behavior related to health care and the factors that influence this behavior. This information will inform policy alternatives to address geographic barriers to health care in rural communities.

Adult↗