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Results for “Longitudinal analysis”

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At least 613 records · Page 34Linked to original sources
PubMed2005

Longitudinal analysis of citrullinated protein/peptide antibodies (anti-CP) during 5 year follow up in early rheumatoid arthritis: anti-CP status predicts worse disease activity and greater radiological progression.

OBJECTIVE: To study serum levels of citrullinated protein/peptide antibodies (anti-CP) during up to 5 years' follow up of patients with early rheumatoid arthritis (RA), and to relate serum levels to disease course and to treatments in clinical practice. METHODS: 279 patients with early RA were followed up with clinical investigations, radiographs, and measurement of anti-CP at baseline and after 3 months, 1, 2, 3, and 5 years. RESULTS: 160/279 (57.3%) patients were anti-CP positive at the first visit (mean 5 months after first symptoms). During follow up only 11/279 (3.9%) of the patients changed their anti-CP status. Anti-CP levels fell significantly during the first year, and this drop correlated with the extent of sulfasalazine treatment but not with other drugs or clinical indices. Anti-CP positive and negative patients had similar disease activities at baseline, but during follow up the anti-CP positive patients had worse clinical disease and greater radiological progression, despite at least equally intensive antirheumatic treatment. CONCLUSIONS: Anti-CP are stable during the first 5 years of RA, suggesting that events before rather than after onset of clinical manifestations of disease determine this phenotype. The presence of anti-CP at diagnosis predicts a less favourable disease course and greater radiological progression despite antirheumatic treatment, but subsequent changes in antibody levels do not reflect changes in disease activity. Taken together, these observations suggest that anti-CP positive RA is a distinct clinical and pathophysiological entity.

Antirheumatic Agents↗
PubMed1993

Evolution of osteoarticular disorders as a function of past heavy physical work factors: longitudinal analysis of 627 retired subjects living in the Paris area.

The relations between osteoarticular disorders and occupational exposure to heavy physical work factors were studied in a random sample of retired subjects living in the Paris area, all of whom had contributed to the same retirement pension fund. 627 subjects were originally seen in 1982-3 and 464 of them were seen again five years later. On both occasions, the same questionnaire was completed during a home interview. Osteoarticular disorders were evaluated by the presence of pain, with or without restricted joint movement, for at least six months before interview. The heavy physical work factors were those reported by the subject at the first interview, and only subjects who stated that they had been exposed to these factors for more than 10 years were considered as exposed persons. For those who were seen twice, the frequency of osteoarticular pain increased during the five years between the two interviews, from 52% to 65% in the men and 72% to 82% in the women. Among both sexes, these frequencies were significantly higher in those who stated that in the past they had to carry heavy weights and work in tiring positions. The increases in frequency of pain during the five year study period were also related to these occupational factors. In general, the frequencies for subjects not exposed to occupational factors caught up with those found for the exposed group. This interaction of age with the relation between exposure to heavy physical work factors and osteoarticular disorders does not seem to be explained by confounding factors, including age at the first interview, the fact of living alone, of being a former manual worker, of having a cardiorespiratory disorder, and smoking habits. The results of the survey suggest that working conditions are an important cause of osteoarticular disorders that last well beyond the end of working life.

Aged↗
PubMed2003

Gonorrhoea reinfection in heterosexual STD clinic attendees: longitudinal analysis of risks for first reinfection.

OBJECTIVES: Gonorrhoea is associated with adverse reproductive health outcomes, including pelvic inflammatory disease and increased HIV transmission. Our objective was to determine the association of demographic factors, sexual risk behaviours, and drug use with incident gonorrhoea reinfection among public STD clinic clients. METHODS: A retrospective cohort study conducted from January 1994 through October 1998, of heterosexual public STD clinic attendees age >/=12 years having at least one gonorrhoea infection in Baltimore, MD. The outcome was first incident gonorrhoea reinfection over a maximum 4.8 years, compared in STD clinic clients with or without sexual risk behaviours and drug use at initial gonorrhoea infection. RESULTS: 910 reinfections occurred among 8327 individuals and 21 246 person years of observation, for an overall incidence of 4.28 reinfections per 100 person years (95% CI 4.03 to 4.53). Median time to reinfection was 1.00 year (95% CI 0.91 to 1.07 years). In multivariate Cox regression, increased reinfection risk was associated with male sex, younger age, greater number of recent sex partners, and having a sex partner who is a commercial sex worker. Injection drug use and coming to the clinic as an STD contact were protective. Among risk factors that differed significantly between men and women, injection drug use was protective of reinfection in men, and "any" condom use was a risk factor for reinfection in women CONCLUSIONS: Reinfection represents a significant proportion of STD clinic visits for gonorrhoea. Prevention counselling and routine screening for patients at high risk for reinfection should be considered to maximally reduce transmission and resource utilisation.

Adult↗
PubMed1991

Daily stressors and systemic lupus erythematosus: a longitudinal analysis--first findings.

Patients with systemic lupus erythematosus (SLE) and a comparison group of patients with rheumatoid arthritis (RA) completed the Dutch Everyday Problem Checklist and the Dutch Arthritis Impact Measurement Scale measuring physical and psychosocial aspects of illness. Both scales were completed 9 times at 6-week intervals. In addition several hematological and serological parameters were assayed. Analysis over several time points resulted in only weak correlations between the variables under study. The most remarkable finding of this study was that in SLE patients number and intensity of daily stressors are more strongly related to physical and psychosocial status than in RA patients.

Activities of Daily Living↗
PubMed2001

Longitudinal analysis of T-cell receptor gene use by CD8(+) T cells in early human immunodeficiency virus infection in patients receiving highly active antiretroviral therapy.

The effects of early antiretroviral therapy on the peripheral CD8(+) T-cell population were assessed by sequentially determining the T-cell receptor (TCR) repertoire complexity in a cohort of 15 individuals recently diagnosed with human immunodeficiency virus infection. Analysis was based on quantitative TCR variable B gene (TCRBV) usage and complementary-determining region 3 length assessment. Repertories were assessed at baseline and at weeks 2, 4, 12, 24, and 72 after initiation of therapy. Early administration of highly active antiretroviral therapy has a positive effect on the preservation and homeostasis of the CD8(+) cell repertoire. Nevertheless, differences from average baseline and control TCR profiles and initial development of repertoire perturbations were observed. The findings suggest that additional therapeutic protocols will be required during primary infection to significantly prevent long-term erosion of the T-cell-mediated immune response.

Adult↗
PubMed2003

A longitudinal analysis of the risk factors for diabetes and coronary heart disease in the Framingham Offspring Study.

BACKGROUND: The recent trends in sedentary life-styles and weight gain are likely to contribute to chronic conditions such as hypertension, diabetes, and cardiovascular diseases. The temporal sequence and pathways underlying these conditions can be modeled using the knowledge from the biomedical and social sciences. METHODS: The Framingham Offspring Study in the U.S. collected information on 5124 subjects at baseline, and 8, 12, 16, and 20 years after the baseline. Dynamic random effects models were estimated for the subjects' weight, LDL and HDL cholesterol, and blood pressure using 4 time observations. Logistic and probit models were estimated for the probability of diabetes and coronary heart disease (CHD) events. RESULTS: The subjects' age, physical activity, alcohol consumption, and cigarettes smoked were important predictors of the risk factors. Moreover, weight and height were found to differentially affect the probabilities of diabetes and CHD events; body weight was positively associated with the risk of diabetes while taller individuals had lower risk of CHD events. CONCLUSION: The results showed the importance of joint modeling of body weight, LDL and HDL cholesterol, and blood pressure that are risk factors for diabetes and CHD events. Lower body weight and LDL concentrations and higher HDL levels achieved via physical exercise are likely to reduce diabetes and CHD events.

Journal Article↗
PubMed1989

Use of longitudinal analysis of peripheral blood counts to validate historical reconstructions of benzene exposure.

We studied over 17,000 peripheral blood counts, accumulated during hematologic surveillance from 1940 through 1975, from a cohort of 459 benzene-exposed workers. Linear regressions demonstrated significant decreases in white and red cell counts, as well as hemoglobin, for workers exposed during the 1940s, without persistent trends over the ensuing 25 years. Strongly positive correlations were observed between these blood count fluctuations and fluctuations in retrospective estimates of benzene exposures for these workers in the earlier period of surveillance (mean estimated exposure 1940 to 1948, 75 ppm), but not for later years, (mean estimated exposure 1948 to 1975, 15 to 20 ppm). These data suggest substantial limitations of hematologic examination of populations to detect abnormalities in populations currently exposed to benzene. The analysis also demonstrates a novel approach to the biological validation of exposure estimates based upon limited industrial hygiene and historical record data. The application of biologic monitoring data may be useful for assisting decisions in reconstruction of a previous exposure.

Air Pollutants, Occupational↗
PubMed2006

Longitudinal analysis of the impact and cost of person-centered planning for people with intellectual disabilities in England.

Person-centered planning is central to United Kingdom policies regarding the support of people with intellectual disabilities. However, little evidence exists on the impact or cost of introducing person-centered planning. We examined the efficacy, effectiveness, and costs of introducing person-centered planning for 93 people with intellectual disabilities over 2 years across four localities in England. A person-centered plan was successfully developed for 65 people. Little change was apparent prior to introducing person-centered planning. After its introduction, modest positive changes were found in the areas of social networks; contact with family; contact with friends; community-based activities; scheduled day activities; and choice. The direct training and support cost of introducing person-centered planning was $1,202 per participant; indirect costs were negligible.

Activities of Daily Living↗
PubMed1998

Bone metabolism after human parturition and the effect of lactation: longitudinal analysis of serum bone-related proteins and bone mineral content of the lumbar spine.

A prospective study was performed to investigate postpartum changes in human bone metabolism and the effects of lactation on them. The subjects consisted of two groups: 13 women who stopped breast-feeding within 3 months postpartum (short-term group) and 14 women who continued breast-feeding for more than 6 months postpartum (long-term group). Serum carboxyl-terminal propeptide of type I procollagen (PICP), carboxyl terminal cross-linked telopeptide of type I collagen (ICTP), and bone gla protein (BGP) were measured prepartum, and at 5 days, 1 month, 3 months and 9 months postpartum. Lumbar BMD was measured at 3-7 days, 3 months and 9 months postpartum. Between prepartum and 3 months postpartum, the values and variations in the markers were essentially the same in both groups. PICP was maintained at a constant and significantly higher level than the control value. In contrast, ICTP had increased markedly at 5 days postpartum, gradually decreasing thereafter. BGP was low prepartum and gradually increased. At 9 months postpartum, PICP and ICTP decreased to the control values in the short-term group. The postpartum time course of lumbar BMD showed a significant decrease in both groups at 3 months postpartum. Recovery to the puerperal level was seen at 9 months postpartum in the short-term group but not in the long-term group. In conclusion, bone resorption is stimulated by parturition as well as lactation resulting in postpartum loss of lumbar BMD.

Adult↗
PubMed1999

Longitudinal analysis of methicillin-resistant Staphylococcus aureus isolates at a teaching hospital in Taiwan.

In Taiwan, the frequency of nosocomial infections caused by methicillin-resistant Staphylococcus aureus (MRSA) has increased rapidly during the past 10 years. To investigate the epidemiology of MRSA infections, a total of 140 MRSA isolates collected at National Taiwan University Hospital from 1992 to 1996 were characterized by pulsed-field gel electrophoresis (PFGE) profiles and antibiotypes, as determined with the disk diffusion method. Among these isolates, six PFGE types (with 20 subtypes) and six antibiotypes were identified. Antibiotyping proved to be a poor method of epidemiologic analysis, because almost all of the MRSA isolates analyzed shared a very similar multidrug-resistant antibiotype. Most MRSA infections and colonizations in this hospital were due to the spread of strains belonging to three major PFGE types (A, B, and C). However, the major type changed in different years with types A, B, and C being predominant in 1992 through 1993, 1994 through 1995, and 1996, respectively. The three major PFGE types spread easily throughout the hospital wards, presumably carried by health care workers and environmental contamination. Our results demonstrate that there was a dominant strain spreading in our hospital each year and the dominant strain may shift in different years.

Bacterial Typing Techniques↗
PubMed2001

A longitudinal analysis of the distinction between for-profit and not-for-profit hospitals in America.

Have changes in the hospital industry forced not-for-profit hospitals to become more like for-profit hospitals in measures of efficiency and community service? As a result, are not-for-profit hospitals moving away from their community service missions? In recent years researchers have asserted that the once-salient distinctions between not-for-profit and for-profit hospitals are quickly eroding and that this convergence threatens the community service that not-for-profit hospitals have historically provided. Neo-institutionalists explain that regulatory changes often force differing organization types to pursue similar strategies (Fligstein 1991, 1985; DiMaggio and Powell 1983). Guided by this theory, the present research analyzes if regulatory changes and the implementation of similar strategies result in not-for-profit and for-profit hospitals having similar efficiency and community service outcomes.

Efficiency, Organizational↗
PubMed2002

Longitudinal analysis of the relationship between changes in smoking and changes in drinking in a community sample: the Winnipeg Health and Drinking Survey.

Smoking cigarettes and drinking alcohol are positively correlated in cross-sectional studies of the general population. However, it is unclear whether changes in quantity of drinking over time are related to changes in amount of smoking over time. This investigation examined, with structural equation modeling, the relationship of changes in drinking to changes in smoking over 2 years among 344 adults who reported cigarette smoking and alcohol use at baseline in 1989-1990 or at follow-up in 1991-1992 or both. Surprisingly, no significant relationships were found between changes in smoking and changes in drinking. This lack of effect suggests that changes in the quantity or intensity of drinking and of smoking are not related in any important way in nonclinical populations.

Adolescent↗