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M Zwahlen

Publications and source records attributed to M Zwahlen.

At least 19 recordsLinked to original sources
PubMed2008

Incidence of childhood cancer in Switzerland: the Swiss Childhood Cancer Registry.

BACKGROUND: This report describes the incidence of childhood cancer in Switzerland, based on the data from the Swiss Childhood Cancer Registry (SCCR), a national hospital-based cancer registry with very high coverage, founded in 1976 by the Swiss Paediatric Oncology Group (SPOG). PROCEDURE: Malignancies were coded according to the International Classification of Childhood Cancer (ICCC-3). Incidence rates per 100,000 person-years were calculated for all malignancies and groups of malignancies in Swiss residents less than 15 years of age for the decade 1995-2004. RESULTS: The SCCR annually registered on average 174 new cases of cancer in Swiss residents aged <15 years, with a median age at diagnosis of 5.6 years. The crude incidence of childhood cancer in children aged <15 years was 13.5, higher for boys (15.0 per 100,000) than for girls (12.1 per 100,000), and was nearly twice as high in the first 5 years of life (19.3 per 100,000) than in the age group 5 to 14 years (10.8 per 100,000). CONCLUSION: Incidence of childhood cancers in the SCCR was similar to neighbouring countries and to data published by regional cancer registries in Switzerland for the same period, suggesting good completeness of registration. This makes the SCCR a valuable resource for national and international research on childhood cancer.

Adolescent↗
PubMed2007

Prospectively assessed incidence, severity, and determinants of respiratory symptoms in the first year of life.

Respiratory symptoms are common in infancy. Nevertheless, few prospective birth cohort studies have studied the epidemiology of respiratory symptoms in normal infants. The aim of this study was to prospectively obtain reliable data on incidence, severity, and determinants of common respiratory symptoms (including cough and wheeze) in normal infants and to determine factors associated with these symptoms. In a prospective population-based birth cohort, we assessed respiratory symptoms during the first year of life by weekly phone calls to the mothers. Poisson regression was used to examine the association between symptoms and various risk factors. In the first year of life, respiratory symptoms occurred in 181/195 infants (93%), more severe symptoms in 89 (46%). The average infant had respiratory symptoms for 4 weeks and 90% had symptoms for less than 12 weeks (range 0 to 23). Male sex, higher birth weight, maternal asthma, having older siblings and nursery care were associated with more, maternal hay fever with fewer respiratory symptoms. The association with prenatal maternal smoking decreased with time since birth. This study provides reliable data on the frequency of cough and wheeze during the first year of life in healthy infants; this may help in the interpretation of published hospital and community-based studies. The apparently reduced risk in children of mothers with hayfever but no asthma, and the decreasing effect of prenatal smoke exposure over time illustrate the complexity of respiratory pathology in the first year of life.

Asthma↗
PubMed2006

QTc interval and resting heart rate as long-term predictors of mortality in type 1 and type 2 diabetes mellitus: a 23-year follow-up.

AIMS/HYPOTHESIS: We evaluated the association of QT interval corrected for heart rate (QT(c)) and resting heart rate (rHR) with mortality (all-causes, cardiovascular, cardiac, and ischaemic heart disease) in subjects with type 1 and type 2 diabetes. METHODS: We followed 523 diabetic patients (221 with type 1 diabetes, 302 with type 2 diabetes) who were recruited between 1974 and 1977 in Switzerland for the WHO Multinational Study of Vascular Disease in Diabetes. Duration of follow-up was 22.6 +/- 0.6 years. Causes of death were obtained from death certificates, hospital records, post-mortem reports, and additional information given by treating physicians. RESULTS: In subjects with type 1 diabetes QT(c), but not rHR, was associated with an increased risk of: (1) all-cause mortality (hazard ratio [HR] 1.10 per 10 ms increase in QT(c), 95% CI 1.02-1.20, p = 0.011); (2) mortality due to cardiovascular (HR 1.15, 1.02-1.31, p = 0.024); and (3) mortality due to cardiac disease (HR 1.19, 1.03-1.36, p = 0.016). Findings for subjects with type 2 diabetes were different: rHR, but not QT(c) was associated with mortality due to: (1) all causes (HR 1.31 per 10 beats per min, 95% CI 1.15-1.50, p < 0.001); (2) cardiovascular disease (HR 1.43, 1.18-1.73, p < 0.001); (3) cardiac disease (HR 1.45, 1.19-1.76, p < 0.001); and (4) ischaemic heart disease (HR 1.52, 1.21-1.90, p < 0.001). Effect modification of QT(c) by type 1 and rHR by type 2 diabetes was statistically significant (p < 0.05 for all terms of interaction). CONCLUSIONS/INTERPRETATION: QT(c) is associated with long-term mortality in subjects with type 1 diabetes, whereas rHR is related to increased mortality risk in subjects with type 2 diabetes.

Adult↗
PubMed2006

Alterations of exhaled nitric oxide in pre-term infants with chronic lung disease.

Animal models suggest that reduced nitric oxide (NO) synthase activity results in lower values of exhaled NO (eNO) present at birth in those individuals who are going to develop chronic lung disease of infancy (CLDI). Online tidal eNO was measured in 39 unsedated pre-term infants with CLDI (mean gestational age (GA) 27.3 weeks) in comparison with 23 healthy pre-term (31.6 weeks) and 127 term infants (39.9 weeks) at 44 weeks post-conceptional age, thus after the main inflammatory response. NO output (NO output (V'(NO)) = eNO x flow) was calculated to account for tidal- flow-related changes. Sex, maternal atopic disease and environmental factors (smoking, caffeine) were controlled for. The mean eNO was not different (14.9 ppb in all groups) but V'(NO) was lower in CLDI compared with healthy term infants (0.52 versus 0.63 nL x s(-1)). Values for healthy pre-term infants were between these two groups (0.58 nL x s(-1)). Within all pre-term infants (n = 62), V'(NO) was reduced in infants with low GA, high clinical risk index for babies scores and longer duration of oxygen therapy but not associated with post-natal factors, such as ventilation or corticosteroid treatment. After accounting for flow, the lower nitric oxide output in premature infants with chronic lung disease of infancy is consistent with the hypothesis of nitric oxide metabolism being involved in chronic lung disease of infancy.

Breath Tests↗
PubMed2006

Parental understanding of wheeze and its impact on asthma prevalence estimates.

The epidemiology of wheeze in children, when assessed by questionnaires, is dependent on parents' understanding of the term "wheeze". In a questionnaire survey of a random population sample of 4,236 children aged 6-10 yrs, parents' definition of wheeze was assessed. Predictors of a correct definition were determined and the potential impact of incorrect answers on prevalence estimates from the survey was assessed. Current wheeze was reported by 13.2% of children. Overall, 83.5% of parents correctly identified "whistling or squeaking" as the definition of wheeze; the proportion was higher for parents reporting wheezy children (90.4%). Frequent attacks of reported wheeze (adjusted odds ratio (OR) 3.0), maternal history of asthma (OR 1.5) and maternal education (OR 1.5) were significantly associated with a correct answer, while the converse was found for South Asian ethnicity (OR 0.6), first language not English (OR 0.6) and living in a deprived neighbourhood (OR 0.6). In summary, the present study showed that misunderstanding could lead to an important bias in assessing the prevalence of wheeze, resulting in an underestimation in children from South Asian and deprived family backgrounds. Prevalence estimates for the most severe categories of wheeze might be less affected by this bias and questionnaire surveys on wheeze should incorporate measures of parents' understanding of the term wheeze.

Asthma↗
PubMed2006

The therapy of pre-school wheeze: appropriate and fair?

The current study aimed to assess prevalence and distribution of use of asthma medication for wheeze in pre-school children in the community. We sent a postal questionnaire to the parents of a random population-based sample of 4,277 UK children aged 1-5 years; 3,410 participated (children of south Asian decent were deliberately over-represented). During the previous 12 months, 18% of the children were reported to have received bronchodilators, 8% inhaled corticosteroids (ICS) and 3% oral corticosteroids. Among current wheezers these proportions were 55%, 25%, and 12%, respectively. Use of ICS increased with reported severity of wheeze, but did not reach 60% even in the most severe category. In contrast, 42% of children receiving ICS reported no or very infrequent recent wheeze. Among children with the episodic viral wheeze phenotype, 17% received ICS compared with 40% among multiple-trigger wheezers. Use of ICS by current wheezers was less common in children of South Asian ethnicity and in girls. Although a high proportion of pre-school children in the community used asthma inhalers, treatment seemed to be insufficiently adjusted to severity or phenotype of wheeze, with relative under-treatment of severe wheeze with ICS, especially in girls and South Asian children, but apparent over-treatment of mild and episodic viral wheeze and chronic cough.

Asthma↗
PubMed2006

Apolipoprotein B as a long-term predictor of mortality in type 1 diabetes mellitus: a 15-year follow up.

OBJECTIVES: To evaluate the association of apolipoprotein B (apo B) with mortality due to all causes, to cardiac disease and to ischaemic heart disease (IHD) in subjects with type 1 diabetes mellitus. SUBJECTS: 165 subjects with type 1 diabetes included in the Swiss Cohort of the WHO Multinational Study of Vascular Disease in Diabetes were followed for 14.7+/-0.45 years. METHODS: Causes of death were obtained from death certificates, hospital records and postmortem reports. Using a parametric proportional hazards model the association of apo B with mortality rates was assessed by time-to-event analysis, including the absolute cumulative mortality risk over time for various apo B levels at baseline. RESULTS: Apo B was positively associated with all-cause mortality [hazard ratio (HR) 2.65 per g L-1 increase of apo B, 95% CI: 1.11-6.36, P=0.029], cardiac mortality (HR 11.64, 1.03-131.11, P=0.047) and IHD mortality (HR 9.36, 1.26-69.66, P=0.029). An apo B>or=0.96 g L-1 translated into a duplication of overall mortality hazard (HR 1.93, 1.00-3.72, P=0.050), and a sevenfold increase of mortality because of cardiac disease or IHD (HR 7.44, 1.44-38.42, P=0.017 and HR 7.38, 0.78-69.82, P=0.081). A baseline apo B of 1.5 g L-1 predicted an absolute cumulative risk to die over the next 10 years of 12.1% (5.2-31.7) for male and of 10.4% (4.7-26.1) for female subjects whereas risks were 6.3% (1.8-21.4) and 5.4% (0.8-15.8) for an apo B of 0.8 g L-1. CONCLUSION: Apo B is consistently associated with an increased mortality in type 1 diabetes.

Apolipoproteins B↗
PubMed2005

Treatment outcomes and mortality of 94 patients with acromegaly.

BACKGROUND: Due to new therapeutic modalities and modified therapeutic goals outcome of patients with acromegaly may change over time and differ by centre. We analysed treatment outcomes and mortality of our patients with acromegaly seen between 1971 and 2003. METHOD: The cohort consisted of 94 patients who had been followed for 0.3-31 years (mean 10.6 years). Remission criteria were a normalized IGF-I concentration, a nadir GH level during oral glucose load of <1.0 microg/l and a random GH value of <2.5 microg/l. FINDINGS: Transsphenoidal surgery achieved remission in 80% of patients with micro-adenomas (<1 cm), 65% with meso-adenomas (> or = 1 cm to <2 cm) and 27% with macro-adenomas (> or = 2 cm). Patients with meso-adenomas operated on after 1995 tended to have a better outcome compared to those operated on before 1995 (Remission in 83% vs. 38%). Radiotherapy resulted in disease control in 22 of 47 patients (47%). Intramuscular depot formulation of octreotide (Sandostatin LAR) led to disease control in 17 of 26 patients (65%). After multimodal therapy persistent acromegalic activity remained in 18% of the patients; only one of them had an adenoma of <2 cm. The standardized mortality ratio was 1.30 (95% CI 0.52-2.67) for patients in remission and 1.38 (95% CI 0.51-3.00) for patients with persistent acromegalic activity. CONCLUSIONS. Most patients with adenomas of <2 cm can be expected to achieve remission by transsphenoidal surgery alone. Furthermore, virtually all patients with adenomas of <2 cm and more than 80% of patients with adenomas of > or = 2 cm can be expected to achieve remission by adjuvant treatment. Aggressive multimodal therapy is critical in the management of acromegaly reducing mortality risk close to that of the general population.

Acromegaly↗
PubMed2004

[The Swiss HIV Cohort Study--resource for epidemiology and public health].

The epidemiological situation in Switzerland was characterised by a substantial decline in the number of AIDS cases and HIV-related deaths following the introduction of highly active antiretroviral therapy (HAART). The number of new HIV infections, has, however increased in recent years and AIDS cases and related deaths are no longer declining. We discuss three examples of issues that are relevant to epidemiology and public health in order to illustrate the importance of the study in this context: (i) use of SHCS data to inform the interpretation of routine surveillance data based on reports from physicians and laboratories to the Federal Office of Public Health (FOPH); (ii) analyses of access to and utilization of HAART across different groups of study participants, including migrant populations, those with lower socio-economic status and patients infected through intravenous drug use; and (iii) the monitoring of trends in self-reported sexual behaviour, including condom use with stable and casual partners. The examples demonstrate that the study is an important resource for epidemiological analysis and public health surveillance and action in Switzerland.

Acquired Immunodeficiency Syndrome↗
PubMed2001

HIV and hepatitis virus infections among injecting drug users in a medically controlled heroin prescription programme.

BACKGROUND: In Switzerland, 1,035 patients were accepted for admission to the medically controlled prescription of narcotics programme (PROVE) from 1 January 1994 until 31 December 1996. Heroin, methadone, and morphine were prescribed. This paper presents the prevalence and incidence of HIV and hepatitis B/C infections in the sociomedical context of the participants. METHODS: Admission criteria were a minimum age of 20 years, at least a two-year duration of daily heroin consumption, a negative outcome of at least two previous treatments, and documented social and health deficits as a consequence of their heroin dependence. The patients were examined at admission and every six months. A serological test was carried out at the same time for HIV and hepatitis B/C. RESULTS: Serological testing on admission could be performed in more than 80% of the entrants and documented a very high seroprevalence of antibodies against HBcore (73%) and HCV (82%). The prevalence of HIV and hepatitis B/C increased with duration of drug intake. In the follow-up analysis of seronegative individuals, a halving of the risk of viral hepatitis infection was shown when comparing the first six months with the period greater then six months after PROVE entry. CONCLUSION: The tests conducted showed high prevalence and incidence rates of HIV and hepatitis B/C among patients who had consumed intravenous drugs for years. The descriptive analysis in heroin-assisted treatment showed a reduction in infection risk for viral hepatitis corresponding to the lower risk behaviour of patients.

Adult↗
PubMed2000

[Herpes simplex virus type 1 and 2 in Switzerland].

A worldwide increase in the incidence of genital herpes infections has been described in recent years. Transmission of the herpes simplex virus type 2 (HSV-2) by asymptomatic seropositive subjects is considered to be a relevant mode of infection. The seroprevalence of HSV-2 varies considerably between different populations. In Europe, data are scarce and the epidemiological situation in Switzerland is unknown. In 1997 we performed serological examinations in 151 adult volunteers (87% between 20 and 49 years of age) of a low-risk population from the region of Basel with no history of genital herpes or any other sexually transmitted disease. The overall seroprevalence of HSV-1 was 77% and an annual seroconversion rate of 4.6% (95% CI: 3.8-5.6) was estimated for both sexes. Of the 51 subjects with no symptoms of orolabial herpes, 25 (49%) proved to be HSV-1 seropositive. In contrast, of 91 patients with symptoms of orolabial herpes, 90 (97%) had serum antibodies against HSV-1. The seroprevalence of HSV-2 was 14.6% for women (n = 89) and 8.1% for men (n = 62). The annual seroconversion rate was estimated to be 0.61% (95% CI: 0.14-1.4) for women and 0.49% (95% CI: 0.09-1.4) for men for the period after 1985 (when "safer sex" and the use of condoms were promoted). Our results indicate the significance of herpes simplex virus type 2 infections in Switzerland. More detailed studies are needed to describe the epidemiology of HSV-2 infections more reliably, especially in view of progress in the development of vaccines against HSV infections.

Adult↗
PubMed2000

HIV testing and retesting for men and women in Switzerland.

This study was conducted to describe voluntary HIV testing in the general population in Switzerland and to estimate yearly HIV test incidence. In 1994, a representative telephone survey of individuals aged 17 to 45 years obtained self-reported information on HIV testing. In addition to describing cumulative HIV test incidence, yearly HIV test incidence over time was estimated by a Bayesian hurdle model allowing for the plausible scenario of test consumption differing between first test and subsequent retests. Overall, 33% of the Swiss population (age 17 to 45 years) has been tested at some time for HIV on a voluntary basis (30% men, 36% women). For the time period 1990-1994, the result showed for 35-year-old individuals with supposedly low risk behavior, that 1) annual test incidence (first test or retest) showed a greater increase for men (4.2 to 5.9%) than for women (5.0 to 6.0%); 2) annual first test incidence increased moderately and differed for men and women (2.9 to 3.4% for men, 4.6 to 5.2% for women), and 3) annual retest incidence was twice as high for men (17.6%) as for women (8.6%). In conclusion, a substantial part of the Swiss population has been tested at some stage for HIV on a voluntary basis, and differences exist for testing and retesting between men and women.

Adolescent↗
PubMed2000

Trends in the prevalence of infection with mycobacterium tuberculosis in Korea from 1965 to 1995: an analysis of seven surveys by mixture models.

SETTING: Korea. OBJECTIVE: Estimation of the prevalence of tuberculous infection from tuberculin skin test surveys can be difficult if cross-reactions resulting from infection with environmental mycobacteria outweigh reactions resulting from tuberculous infection. Mixture analysis was thus chosen as a novel approach for estimating the prevalence of tuberculous infection in Korea. DESIGN: Seven tuberculin skin test surveys conducted between 1965 and 1995 were analyzed by mixture models, a statistical methodology used either to estimate a prevalence or to classify individuals into predefined homogeneous sub-populations. A Bayesian approach including prior information on component distributions was taken. The final model was selected based on the fit to observed values, and the analysis was therefore stratified by sex and year of survey and included age as a covariate. RESULTS: The results showed a large decrease in tuberculous infection in the population below 30 years of age: among 10- to 14-year-old boys (girls), infection prevalence decreased from 74.5% (67.9%) in 1965 to 16.5% (16.9%) in 1995. Additionally, the mean induration for individuals with tuberculous infection decreased by 2mm between 1965 and 1995, indicating a changing sensitivity of tuberculin over time. CONCLUSIONS: Mixture analysis is a promising approach for determining the prevalence of tuberculous infection in the presence of substantial interference from infection with environmental mycobacteria and changing tuberculin reaction sizes over time.

Adolescent↗
PubMed1999

High frequency of non-B subtypes in newly diagnosed HIV-1 infections in Switzerland.

HIV-1 subtypes were determined in newly diagnosed residents of Switzerland. Blood was anonymously collected from patients with a first confirmed positive HIV-1 test result. Viral DNA from the env V3-V5 region was amplified by nested polymerase chain reaction (PCR) and screened for subtype B by heteroduplex mobility assay. All amplicons not identified as B were sequenced. From November 1996 to February 1998, 206 samples were analyzed. Main transmission risks were unprotected heterosexual (55.7%) or homosexual (27.1%) sexual contact or intravenous drug use (12.9%). Subtype B dominated in patients of Swiss, other European, American, or Asian citizenship; particularly high frequencies were found in homosexuals (97%) and drug users (94%). Non-B subtypes including A, C, D, E, F, G, H, a possible B/F recombinant, and a sequence related to J were present in 28.2% (95% confidence interval [CI], 22.9%-35.0%). Non-B were frequent in African citizens (95%), heterosexually infected individuals (44%), and women (43%). Heterosexually infected Swiss males harbored non-B strains in 18% and females in 33%. The results document a change in the epidemiology of newly diagnosed HIV-1 infections in Switzerland: predominance of heterosexual transmission and a high frequency of non-B subtypes.

Adult↗
PubMed1999

The Swiss Network of Dermatology Policlinics HIV prevalence study: rationale, characteristics and results (1990-1996).

The Swiss Network of Dermatology Policlinics (SNDP) has monitored the prevalence of HIV among patients treated for a sexually transmitted disease (STD) since January 1990. A questionnaire was sent to each policlinic in the network (Basel, Bern, Geneva, Lausanne, and two in Zurich) to collect information on their participation in this study and the characteristics of the network. The responses reveal that the six policlinics followed the HIV prevalence study protocol in a uniform manner and had similar logistical and organisational characteristics HIV prevalences in this population were high (1.6% among heterosexuals, 24.0% among male homo/bisexuals, and 35.7% among injecting drug users), have remained stable, and vary considerably by policlinic. In conclusion, we found that the policlinics have correctly implemented the HIV prevalence study and that the SNDP is a homogeneous sentinel surveillance system. Knowledge of the organisation and characteristics of the SNDP has allowed us to better interpret and present our data, and we recommend that other sentinel surveillance systems of this type collect this sort of information.

Ambulatory Care Facilities↗
PubMed1998

Mortality from respiratory tuberculosis in Switzerland.

Since 1901, the Swiss Federal Office of Statistics has published at least each decade detailed mortality statistics from tuberculosis. These cross-sectional data on deaths from respiratory tuberculosis from 1901 to 1991 were utilized to analyse retrospectively tuberculosis death experience within each birth cohort. The cross-sectional data indicate that tuberculosis mortality increases with age in each successive decade. Nevertheless, the cohort-contour approach indicates that this phenomenon is the result of a much higher mortality that each cohort experienced in their early adulthood, and that mortality form respiratory tuberculosis in Switzerland always preferentially affected the young. The data also indicate that tuberculosis mortality in Switzerland has been decreasing for at least 160 years, and perhaps peaked as early as in the eighteenth century.

Adolescent↗
PubMed1998

Adjusting AIDS incidence for non-stationary reporting delays: a necessity for country comparisons.

In many industrialized countries, infection with the human immunodeficiency virus (HIV) is one of the leading causes of mortality in adult persons below age 45. The incidence of the acquired immunodeficiency syndrome (AIDS) from surveillance systems is the most common indicator to compare the situation of the HIV-epidemic in different geographic regions or countries. Due to reporting delays, AIDS diagnoses in recent years are incompletely reported and need to be estimated. In this study, we analyze reporting delays in Switzerland and Spain for the period from 1988 to mid-1995 and estimate the number of AIDS diagnoses per year. A descriptive analysis for Switzerland shows increasing reporting delays in recent years. Then, a Bayesian generalized linear model on reverse-time hazards is used to model time trends of the reporting delay distribution. The model shows that in recent years (i) for Switzerland reporting delays became longer and yearly AIDS incidence might continue to increase, and (ii) for Spain, reporting delays became considerably shorter resulting in too large estimates of yearly AIDS incidence if stationarity of reporting delays is assumed. Critical issues of modeling non-stationarity of the reporting system are discussed and it is emphasized that estimates of recent AIDS incidence can be biased significantly if time trends of reporting are ignored-as in the example of Switzerland and Spain, this may severely distort comparisons of the AIDS epidemic in different countries.

Acquired Immunodeficiency Syndrome↗