PubMed Health⌕ Search

Biomedical subjects

M Rickenbach

Publications and source records attributed to M Rickenbach.

At least 19 recordsLinked to original sources
PubMed1999

Why is highly active antiretroviral therapy (HAART) not prescribed or discontinued? Swiss HIV Cohort Study.

In this cross-sectional survey conducted at the end of 1997 among the physicians of participants of the Swiss HIV Cohort Study (SHCS), 1487 of 2154 patients (69.0%) were treated with highly active antiretroviral treatment (HAART) defined as triple therapy with a combination of one or two reverse transcriptase inhibitors, and one or two protease inhibitors; 541 patients (25.1%) had never received such treatment. The physician's perception that the patient would not comply with treatment was one reason for not prescribing HAART to 20% of these patients (110). Physicians indicated that the most common reasons for the patient to refuse HAART were the fear of side effects (18%) and the patient's perception that treatment was too complicated (18%). Among 126 patients (5.8%) no longer receiving HAART, the most common reasons for discontinuing treatment were actual side effects (61%) or the fear of side effects (25%). Overall, 16% of patients did not receive therapy in accord with official Swiss guidelines. Multivariate logistic regression analysis indicated that patients with lower education, active intravenous drug users outside of a drug substitution program, and those who acquired HIV infection through intravenous drug use had a significantly higher risk of inadequate treatment. The physician's judgment of patient adherence and the physician's perception of the patient's fear of side effects are critical for the prescription of HAART. Physicians should address these issues to prevent unilateral withholding of treatment and increase the proportion of patients who may benefit from current antiretroviral therapy.

Anti-HIV Agents↗
PubMed1999

Discontinuation of primary prophylaxis against Pneumocystis carinii pneumonia in HIV-1-infected adults treated with combination antiretroviral therapy. Swiss HIV Cohort Study.

BACKGROUND: It is unclear whether primary prophylaxis against Pneumocystis carinii pneumonia can be discontinued in patients infected with the human immunodeficiency virus (HIV) who are successfully treated with combination antiretroviral therapy. We prospectively studied the safety of stopping prophylaxis among patients in the Swiss HIV Cohort Study. METHODS: Patients were eligible for our study if their CD4 counts had increased to at least 200 cells per cubic millimeter and 14 percent of total lymphocytes while they were receiving combination antiretroviral therapy, with these levels sustained for at least 12 weeks. Prophylaxis was stopped at study entry, and patients were examined every three months thereafter. The development of P. carinii pneumonia was the primary end point, and the development of toxoplasmic encephalitis the secondary end point. RESULTS: Of the 262 patients included in our analysis, 121 (46.2 percent) were positive for IgG antibodies to Toxoplasma gondii at base line. The median CD4 count at study entry was 325 per cubic millimeter (range, 210 to 806); the median nadir CD4 count was 110 per cubic millimeter (range, 0 to 240). During a median follow-up of 11.3 months (range, 3.0 to 18.8), prophylaxis was resumed in nine patients, and two patients died. There were no cases of P. carinii pneumonia or toxoplasmic encephalitis. The one-sided upper 99 percent confidence limit for the incidence of P. carinii pneumonia was 1.9 cases per 100 patient-years (based on 238 patient-years of follow-up). The corresponding figure for toxoplasmic encephalitis was 4.2 per 100 patient-years (based on 110 patient-years of follow-up). CONCLUSIONS: Stopping primary prophylaxis against P. carinii pneumonia appears to be safe in HIV-infected patients who are receiving combination antiretroviral treatment and who have had a sustained increase in their CD4 counts to at least 200 cells per cubic millimeter and to at least 14 percent of total lymphocytes.

AIDS-Related Opportunistic Infections↗
PubMed1998

Impact of antiretroviral combination therapies on AIDS surveillance reports in Switzerland. Swiss HIV Cohort Study.

BACKGROUND: AIDS reporting in Switzerland is mandatory by law. For the first time since the beginning of the epidemic, health authorities observed a decline in AIDS surveillance reports, from 545 new cases in 1995 to 459 in 1996, a decrease of 86 cases. OBJECTIVE: To examine the extent to which this decline in AIDS surveillance reports is attributable to the introduction of antiretroviral combination therapy. PATIENTS AND SETTING: Swiss HIV Cohort Study, a multicentre cohort of adult HIV-infected patients with national coverage. Participants at risk of developing a first AIDS-defining event, defined as persons with a CD4 cell count below 200 x 10(6)/l or in clinical stage B, were studied. METHODS: A parametric statistical survival model was used to estimate the number of AIDS cases expected in the absence of combination therapies. Taking reporting delays into account, the effect of the introduction of combination therapies in the cohort on national AIDS reports was estimated from the difference between the number of expected and observed cases. RESULTS: A total of 4915 participants contributed 10755 person-years and 2366 initial AIDS events. Between 1990 and 1994, about 35% received antiretroviral therapy, predominantly monotherapy. In 1995 and 1996, the prevalence of antiretroviral therapy increased steadily due to the introduction of dual and triple combinations. The mid-year prevalence of use of combination therapies was 6% in 1994, 13% in 1995, and 48% in 1996. The difference between expected and observed cases per half-year increased from 12 in the first 6 months of 1994 to 69 in the second half of 1996. Taking reporting delays into account, we estimated that 43 (95% confidence interval, 17-69) of the deficit of 86 reports could be attributed to combination therapies. CONCLUSION: The introduction of antiretroviral combination therapies in a single cohort study explained 50% of the decline in national AIDS surveillance reports. Monitoring the use and effectiveness of antiretroviral therapy must become an important component of AIDS surveillance systems.

Acquired Immunodeficiency Syndrome↗
PubMed1998

Time trends in the treatment of acute myocardial infarction in Switzerland from 1986 to 1993: do they reflect the advances in scientific evidence from clinical trials?

Three acute coronary care surveys (1986, 1990, and 1993) were conducted in the Swiss region of Vaud-Fribourg on all men aged 25 to 64 years hospitalized for a definite myocardial infarction (218, 224, and 167 cases). Nearly all patients received anticoagulants and nitrates. The proportion of patients treated increased significantly, between 1986 and 1990, for antiplatelet drugs (from 51% to 96%) and thrombolytics (from 9% to 44%) and, between 1990 and 1993, for beta-blockers (from 57% to 78%) and angiotensin-converting enzyme inhibitors (from 26% to 43%). The use of calcium antagonists and antiarrhythmics dropped over time. Coronary arteriography and angioplasty were increasingly performed (53% and 18% in 1993), although progressively postponed in-hospital stay. The observed trends reflect a rapid translation of clinical trials into medical practice. However the use of thrombolytics could be raised further by shortening the hospitalization delay (median: 3 hours in 1993) and door-to-needle time (median: 47 minutes) which remained stable over time.

Adrenergic beta-Antagonists↗
PubMed1998

[The Swiss HIV Cohort Study--a link between clinical research and medical practice].

The prospective Swiss HIV Cohort Study (SHCS) documents since 1988 epidemiological, clinical and laboratory data of HIV-infected participants. Until the end of 1997, 9447 patients with a total follow-up of 25,584 patient-years have been included. The proportion of women is 27.3% and is rising. The proportion of heterosexually infected patients has been rising since 1992, this group was with 35.6% in 1997 the most frequent transmission category within the newly registered participants. The SHCS is representative for Switzerland since 73% of the 5532 nationwide registered AIDS cases are included in the study. Recently, the SHCS data could demonstrate an impressive reduction in morbidity and mortality due to the improvement in therapy and prophylaxis. The SHCS also serves as a basis for large multicenter studies that aim to evaluate new prophylactic treatments or new antiretroviral strategies. By introducing uniform guidelines for the diagnosis and the treatment of HIV infection, the SHCS has contributed significantly to the high quality of patient care, a goal that must be maintained and further improved in the future. Also important is the recognition of acute HIV infections because early treatment of such patients holds the promise to substantially improve the clinical course.

Acquired Immunodeficiency Syndrome↗
PubMed1997

Impact of new antiretroviral combination therapies in HIV infected patients in Switzerland: prospective multicentre study. Swiss HIV Cohort Study.

OBJECTIVES: To examine trends in disease progression and survival among patients enrolled in the Swiss HIV cohort study during 1988-96 and to assess the influence of new antiretroviral combination therapies. DESIGN: Prospective multicentre study, with follow up visits planned at six monthly intervals. SETTING: Seven HIV units at university centres and cantonal hospitals in Switzerland. PATIENTS: 3785 men (mean age 35.0 years) and 1391 women (30.3 years) infected with HIV. 2023 participants had a history of intravenous drug misuse; 1764 were men who had sex with men; 1261 were infected heterosexually; and 164 had other or unknown modes of transmission. 601 participants had had an AIDS defining illness. RESULTS: During more than 15,000 years of follow up, there were 1456 first AIDS defining diagnoses and 1903 deaths. Compared with those enrolled during 1988-90, the risk of progression to a first AIDS diagnosis was reduced by 18% (relative risk 0.82 (95% confidence interval 0.73 to 0.93)) among participants enrolled in 1991-2, by 23% (0.77 (0.65 to 0.91)) among those enrolled in 1993-4, and by 73% (0.27 (0.18 to 0.39)) among those enrolled in 1995-6. Mortality was reduced by 19% (0.81 (0.73 to 0.90)), 26% (0.74 (0.63 to 0.87)), and 62% (0.38 (0.25 to 0.97)) respectively. Compared with no antiretroviral treatment, the risk of an initial AIDS diagnosis after CD4 lymphocyte counts fell to < 200 cells x 10(6)/1 was reduced by 16% (0.84 (0.73 to 0.97)) with monotherapy, 24% (0.76 (0.63 to 0.91)) with dual therapy, and 42% (0.58 (0.37 to 0.92)) with triple therapy. Mortality was reduced by 23% (0.77 (0.68 to 0.88)), 31% (0.69 (0.60 to 0.80)), and 65% (0.35 (0.20 to 0.60)) respectively. CONCLUSIONS: The introduction of antiretroviral combination therapies outside the selected patient groups included in clinical trials has led to comparable reductions in disease progression and mortality.

Acquired Immunodeficiency Syndrome↗
PubMed1995

Physical activity assessment using a pedometer and its comparison with a questionnaire in a large population survey.

The aim of this study was to evaluate the use of the pedometer in epidemiologic research on physical activity. Within the framework of a health examination survey in 1988-1989, physical activity was assessed in a representative population sample of 493 men and women aged 25-74 years who were residents of Switzerland. They wore a pedometer for 1 week at work and during leisure time, and the results, converted into steps per day, were compared with answers to a questionnaire. The average number of steps per day decreased from 11,900 to 6,700 and from 9,300 to 7,300 for men and women, respectively, in the youngest to the oldest age groups. For men, categorized according to type of physical activity at work, there was a highly significant difference in the number of steps (p < 0.001), whereas in women the results were associated with leisure-time physical activity (p = 0.003). For both sexes, practicing sports more than once a week was associated with an important increase in steps per day. Analyzing the number of steps according to the day of the week and occupational category produced an unexpected result: Men with a physically active job engaged in more leisure-time physical activity on the weekend. The pedometer proved to be useful in assessing physical activity in a large, free-living population.

Adult↗
PubMed1995

Time trend and determinants of blood lead levels in a Swiss population over a transition period (1984-1993) from leaded to unleaded gasoline use.

This study analyzes the trend and determinants of blood lead levels in a Swiss region (population 770,000) over the 10-year period following the introduction of unleaded gasoline in 1985. The consumption of unleaded fuel increased rapidly, accounting in 1988 for 36% and in 1992 for 65% of all gasoline sales. Blood lead levels were measured in three representative samples (n = 1700) of the adult population within the framework of a health examination survey carried out in 1984/1985, 1988/1989, and 1992/1993. The geometric mean blood lead levels were, respectively, 0.59, 0.42, and 0.33 mumole/liter in men, 0.41, 0.29, and 0.25 mumole/liter in women. Similar trends have been observed across all age groups, occupational classes, and categories based on smoking, drinking, and dietary habits. The overexposure of city residents, in comparison to village residents, fades out over the observation period. These findings suggest that the changeover from leaded to unleaded gasoline has been the major cause of the blood lead decline. Wine drinking, cigarette smoking, and age appear to be significant determinants of blood lead for both sexes in all three surveys. In contrast, the association is inverse for milk consumption. The multivariate regression analysis shows that wine drinking remains the most important predictor of blood lead, whereas the influence of age increases with time and overcomes the effect of smoking in the third survey.

Adult↗
PubMed1994

Comparison of serum lipoprotein(a) distribution and its correlates among black and white populations.

BACKGROUND: Epidemiological data on serum lipoprotein(a) (Lp(a)), a presumably strong risk factor for coronary artery disease in White populations, has mostly been derived, in Black populations, from small samples. This study compares the distribution and the determinants of serum Lp(a) in Blacks and in Whites using large representative samples and the same methods in both populations. METHODS: The distribution and the correlates of serum Lp(a) were investigated in population-based samples of 701 Blacks in the Seychelles and 634 Whites in Switzerland, aged 25-64 years. Serum Lp(a) was quantified using a commercial immunoradiometric assay. RESULTS: The distribution of serum Lp(a) was similarly skewed in both ethnic groups, but median Lp(a) concentration was about twofold higher in Blacks (210 mg/l) compared to Whites (100 mg/l). The proportions of individuals with elevated serum Lp(a) (> 300 mg/l) was about 50% higher in Blacks (37.5%) than in Whites (25.2%). In both ethnic groups, serum Lp(a) was found to correlate with total cholesterol, LDL-cholesterol and apoprotein B but not with HDL-cholesterol, alcohol intake, smoking, and body mass index. The variance in serum Lp(a) concentration explained by any combination of these factors was smaller than 5.3% in the two populations. CONCLUSIONS: The measured factors did not explain the higher levels of serum Lp(a) found in Blacks compared to Whites. These findings are consistent with the hypothesis that genetic factors account for much of the variation of serum Lp(a) in both populations.

Adult↗
PubMed1993

[Social class and cardiovascular risk factors in Italian-speaking Switzerland: results of the first Swiss population study MONIKA Project 1985-1986].

The relationship of social class and prevalence of risk factors for cardiovascular diseases was investigated within the Swiss MONICA-project, a cross sectional study of the Swiss-Italian population started in 1985/1986. A representative sample of 984 men and 1014 women ages 35 to 64 was selected, the response rate was 78%. Social class was measured by two indicators, occupational status and education. A significant trend was found in age standardized analysis with higher mean blood pressure and body mass index in lower social classes (p < 0.001). When other confounders for cardiovascular diseases were considered in a multiple regression model, the predictive power of social class was moderate. A significant inverse relationship of cardiovascular risk factors and social class was only found for body mass index (both sexes) and exercise in women which was directly related to higher social class and education. No relationship was found for lipids (cholesterol, HDL-cholesterol), blood pressure and smoking in both sexes. Risk factors for cardiovascular diseases beside obesity do not seem to cluster in lower social classes within the Swiss-Italian population.

Adult↗