Network


Latest external collaboration on country level. Dive into details by clicking on the dots.

Hotspot


Dive into the research topics where Anja Frei is active.

Publication


Featured researches published by Anja Frei.


PLOS ONE | 2013

Smoking cessation induces profound changes in the composition of the intestinal microbiota in humans.

Luc Biedermann; Jonas Zeitz; Jessica Mwinyi; Eveline Sutter-Minder; Ateequr Rehman; Stephan J. Ott; Claudia Steurer-Stey; Anja Frei; Pascal Frei; Michael Scharl; Martin J. Loessner; Stephan R. Vavricka; Michael Fried; Stefan Schreiber; Markus Schuppler; Gerhard Rogler

Background The human intestinal microbiota is a crucial factor in the pathogenesis of various diseases, such as metabolic syndrome or inflammatory bowel disease (IBD). Yet, knowledge about the role of environmental factors such as smoking (which is known to influence theses aforementioned disease states) on the complex microbial composition is sparse. We aimed to investigate the role of smoking cessation on intestinal microbial composition in 10 healthy smoking subjects undergoing controlled smoking cessation. Methods During the observational period of 9 weeks repetitive stool samples were collected. Based on abundance of 16S rRNA genes bacterial composition was analysed and compared to 10 control subjects (5 continuing smokers and 5 non-smokers) by means of Terminal Restriction Fragment Length Polymorphism analysis and high-throughput sequencing. Results Profound shifts in the microbial composition after smoking cessation were observed with an increase of Firmicutes and Actinobacteria and a lower proportion of Bacteroidetes and Proteobacteria on the phylum level. In addition, after smoking cessation there was an increase in microbial diversity. Conclusions These results indicate that smoking is an environmental factor modulating the composition of human gut microbiota. The observed changes after smoking cessation revealed to be similar to the previously reported differences in obese compared to lean humans and mice respectively, suggesting a potential pathogenetic link between weight gain and smoking cessation. In addition they give rise to a potential association of smoking status and the course of IBD.


Thorax | 2014

Determinants and outcomes of physical activity in patients with COPD: a systematic review

Elena Gimeno-Santos; Anja Frei; Claudia Steurer-Stey; Jordi de Batlle; Roberto Rabinovich; Yogini Raste; Nicholas S. Hopkinson; Michael I. Polkey; Hans Van Remoortel; Thierry Troosters; Karoly Kulich; Niklas Karlsson; Milo A. Puhan; Judith Garcia-Aymerich

Background The relationship between physical activity, disease severity, health status and prognosis in patients with COPD has not been systematically assessed. Our aim was to identify and summarise studies assessing associations between physical activity and its determinants and/or outcomes in patients with COPD and to develop a conceptual model for physical activity in COPD. Methods We conducted a systematic search of four databases (Medline, Embase, CINAHL and Psychinfo) prior to November 2012. Teams of two reviewers independently selected articles, extracted data and used the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) to assess quality of evidence. Results 86 studies were included: 59 were focused on determinants, 23 on outcomes and 4 on both. Hyperinflation, exercise capacity, dyspnoea, previous exacerbations, gas exchange, systemic inflammation, quality of life and self-efficacy were consistently related to physical activity, but often based on cross-sectional studies and low-quality evidence. Results from studies of pharmacological and non-pharmacological treatments were inconsistent and the quality of evidence was low to very low. As outcomes, COPD exacerbations and mortality were consistently associated with low levels of physical activity based on moderate quality evidence. Physical activity was associated with other outcomes such as dyspnoea, health-related quality of life, exercise capacity and FEV1 but based on cross-sectional studies and low to very low quality evidence. Conclusions Physical activity level in COPD is consistently associated with mortality and exacerbations, but there is poor evidence about determinants of physical activity, including the impact of treatment.


Health and Quality of Life Outcomes | 2009

Self-efficacy instruments for patients with chronic diseases suffer from methodological limitations - a systematic review

Anja Frei; Anna Svarin; Claudia Steurer-Stey; Milo A. Puhan

BackgroundMeasurement of self-efficacy requires carefully developed and validated instruments. It is currently unclear whether available self-efficacy instruments for chronic diseases fulfill these requirements. Our aim was to systematically identify all existing self-efficacy scales for five major chronic diseases and to assess their development and validation process.MethodsWe conducted a systematic literature search in electronic databases (MEDLINE, PSYCHINFO, and EMBASE) to identify studies describing the development and/or validation process of self-efficacy instruments for the five chronic diseases diabetes, chronic obstructive pulmonary disease (COPD), asthma, arthritis, and heart failure. Two members of the review team independently selected articles meeting inclusion criteria. The self-efficacy instruments were evaluated in terms of their development (aim of instrument, a priori considerations, identification of items, selection of items, development of domains, answer options) and validation (test-retest reliability, internal consistency reliability, validity, responsiveness) process.ResultsOf 584 potentially eligible papers we included 25 (13 for diabetes, 5 for asthma, 4 for arthritis, 3 for COPD, 0 for heart failure) which covered 26 different self-efficacy instrument versions. For 8 instruments (30.8%), the authors described the aim before the scales were developed whereas for the other instruments the aim was unclear. In one study (3.8%) a priori considerations were specified. In none of the studies a systematic literature search was carried out to identify items. The item selection process was often not clearly described (38.5%). Test-retest reliability was assessed for 9 instruments (34.6%), validity using a correlational approach for 18 (69.2%), and responsiveness to change for 3 (11.5%) instruments.ConclusionThe development and validation process of the majority of the self-efficacy instruments had major limitations. The aim of the instruments was often not specified and for most instruments, not all measurement properties that are important to support the specific aim of the instrument (for example responsiveness for evaluative instruments) were assessed. Researchers who develop and validate self-efficacy instruments should adhere more closely to important methodological concepts for development and validation of patient-reported outcomes and report their methods more transparently. We propose a systematic five step approach for the development and validation of self-efficacy instruments.


Thorax | 2017

Physical activity is increased by a 12-week semiautomated telecoaching programme in patients with COPD: a multicentre randomised controlled trial

Heleen Demeyer; Zafeiris Louvaris; Anja Frei; Roberto Rabinovich; C de Jong; Elena Gimeno-Santos; Matthias Loeckx; Sara Buttery; Noah Rubio; T. van der Molen; Nicholas S. Hopkinson; I. Vogiatzis; Milo A. Puhan; Judith Garcia-Aymerich; Michael I. Polkey; Thierry Troosters

Rationale Reduced physical activity (PA) in patients with COPD is associated with a poor prognosis. Increasing PA is a key therapeutic target, but thus far few strategies have been found effective in this patient group. Objectives To investigate the effectiveness of a 12-week semiautomated telecoaching intervention on PA in patients with COPD in a multicentre European randomised controlled trial. Methods 343 patients from six centres, encompassing a wide spectrum of disease severity, were randomly allocated to either a usual care group (UCG) or a telecoaching intervention group (IG) between June and December 2014. This 12-week intervention included an exercise booklet and a step counter providing feedback both directly and via a dedicated smartphone application. The latter provided an individualised daily activity goal (steps) revised weekly and text messages as well as allowing occasional telephone contacts with investigators. PA was measured using accelerometry during 1 week preceding randomisation and during week 12. Secondary outcomes included exercise capacity and health status. Analyses were based on modified intention to treat. Main results Both groups were comparable at baseline in terms of factors influencing PA. At 12 weeks, the intervention yielded a between-group difference of mean, 95% CI (lower limit – upper limit; ll-ul) +1469, 95% CI (971 to 1965) steps/day and +10.4, 95% CI (6.1 to 14.7) min/day moderate PA; favouring the IG (all p≤0.001). The change in 6-min walk distance was significantly different (13.4, 95% CI (3.40 to 23.5) m, p<0.01), favouring the IG. In IG patients, an improvement could be observed in the functional state domain of the clinical COPD questionnaire (p=0.03) compared with UCG. Other health status outcomes did not differ. Conclusions The amount and intensity of PA can be significantly increased in patients with COPD using a 12-week semiautomated telecoaching intervention including a step counter and an application installed on a smartphone. Trial registration number: NCT02158065.


Health and Quality of Life Outcomes | 2011

Validity of instruments to measure physical activity may be questionable due to a lack of conceptual frameworks: a systematic review

Elena Gimeno-Santos; Anja Frei; Fabienne Dobbels; Katja Rüdell; Milo A. Puhan; Judith Garcia-Aymerich

BackgroundGuidance documents for the development and validation of patient-reported outcomes (PROs) advise the use of conceptual frameworks, which outline the structure of the concept that a PRO aims to measure. It is unknown whether currently available PROs are based on conceptual frameworks. This study, which was limited to a specific case, had the following aims: (i) to identify conceptual frameworks of physical activity in chronic respiratory patients or similar populations (chronic heart disease patients or the elderly) and (ii) to assess whether the development and validation of PROs to measure physical activity in these populations were based on a conceptual framework of physical activity.MethodsTwo systematic reviews were conducted through searches of the Medline, Embase, PsycINFO, and Cinahl databases prior to January 2010.ResultsIn the first review, only 2 out of 581 references pertaining to physical activity in the defined populations provided a conceptual framework of physical activity in COPD patients. In the second review, out of 103 studies developing PROs to measure physical activity or related constructs, none were based on a conceptual framework of physical activity.ConclusionsThese findings raise concerns about how the large body of evidence from studies that use physical activity PRO instruments should be evaluated by health care providers, guideline developers, and regulatory agencies.


Chest | 2014

No Association of 25-Hydroxyvitamin D With Exacerbations in Primary Care Patients With COPD

Milo A. Puhan; Lara Siebeling; Anja Frei; Marco Zoller; Heike A. Bischoff-Ferrari; Gerben ter Riet

BACKGROUND Cross-sectional studies suggest an association of 25-hydroxyvitamin D with exacerbations in patients with COPD, but longitudinal evidence from cohort studies is scarce. The aim of this study was to assess the association of serum 25-hydroxyvitamin D with exacerbations and mortality in primary care patients with COPD. METHODS In the main analysis, we included 356 patients with COPD (GOLD [Global Initiative for Chronic Obstructive Lung Disease] stages II-IV, free from exacerbations for ≥ 4 weeks) from a prospective cohort study in Dutch and Swiss primary care settings. We used negative binomial and Cox regression to assess the association of 25-hydroxyvitamin D with (centrally adjudicated) exacerbations and mortality, respectively. RESULTS Baseline mean ± SD serum 25-hydroxyvitamin D concentration was 15.5 ± 8.9 ng/dL, and 274 patients (77.0%) had 25-hydroxyvitamin D deficiency (< 20 ng/dL). Compared with patients with severe 25-hydroxyvitamin D deficiency (< 10 ng/dL, n = 106 [29.8%]), patients with moderately deficient (10-19.99 ng/dL, n = 168 [47.2%]) and insufficient (20-29.99 ng/dL, n = 58 [16.3%]) concentrations had the same risk for exacerbations (incidence rate ratio, 1.01 [95% CI, 0.77-1.57] vs 1.00 [95% CI, 0.62-1.61], respectively). In patients with desirable concentrations (> 30 ng/dL, n = 24 [6.7%]), the risk was lower, although not significantly (incidence rate ratio, 0.72 [95% CI, 0.37-1.42]). In patients taking vitamin D supplements, using different cutoffs for 25-hydroxyvitamin D or competing risk models did not materially change the results. We did not find a statistically significant association of 25-hydroxyvitamin D concentration with mortality. CONCLUSIONS This longitudinal study in a real-world COPD population that carefully minimized misclassification of exacerbations and the influence of confounding did not show an association of 25-hydroxyvitamin D with exacerbations and mortality.


European Respiratory Journal | 2014

The PROactive innovative conceptual framework on physical activity.

Fabienne Dobbels; Corina de Jong; Ellen Drost; J.E. Elberse; Chryssoula Feridou; Laura Jacobs; Roberto Rabinovich; Anja Frei; Milo A. Puhan; Willem I. de Boer; Thys van der Molen; Kate Williams; H Pinnock; Thierry Troosters; Niklas Karlsson; Karoly Kulich; Katja Rüdell

Although physical activity is considered an important therapeutic target in chronic obstructive pulmonary disease (COPD), what “physical activity” means to COPD patients and how their perspective is best measured is poorly understood. We designed a conceptual framework, guiding the development and content validation of two patient reported outcome (PRO) instruments on physical activity (PROactive PRO instruments). 116 patients from four European countries with diverse demographics and COPD phenotypes participated in three consecutive qualitative studies (63% male, age mean±sd 66±9 years, 35% Global Initiative for Chronic Obstructive Lung Disease stage III–IV). 23 interviews and eight focus groups (n = 54) identified the main themes and candidate items of the framework. 39 cognitive debriefings allowed the clarity of the items and instructions to be optimised. Three themes emerged, i.e. impact of COPD on amount of physical activity, symptoms experienced during physical activity, and adaptations made to facilitate physical activity. The themes were similar irrespective of country, demographic or disease characteristics. Iterative rounds of appraisal and refinement of candidate items resulted in 30 items with a daily recall period and 34 items with a 7-day recall period. For the first time, our approach provides comprehensive insight on physical activity from the COPD patients’ perspective. The PROactive PRO instruments’ content validity represents the pivotal basis for empirically based item reduction and validation. Conceptual framework as basis of PROactive PRO instruments to assess physical activity from COPD patient perspective http://ow.ly/ytJoS


Diabetes Care | 2014

Implementation of the Chronic Care Model in Small Medical Practices Improves Cardiovascular Risk but Not Glycemic Control

Anja Frei; Oliver Senn; Corinne Chmiel; Josiane Reissner; Ulrike Held; Thomas Rosemann

OBJECTIVE To test whether the implementation of elements of the Chronic Care Model (CCM) via a specially trained practice nurse leads to an improved cardiovascular risk profile among type 2 diabetes patients. RESEARCH DESIGN AND METHODS This cluster randomized controlled trial with primary care physicians as the unit of randomization was conducted in the German part of Switzerland. Three hundred twenty-six type 2 diabetes patients (age >18 years; at least one glycosylated hemoglobin [HbA1c] level of ≥7.0% [53 mmol/mol] in the preceding year) from 30 primary care practices participated. The intervention included implementation of CCM elements and involvement of practice nurses in the care of type 2 diabetes patients. Primary outcome was HbA1c levels. The secondary outcomes were blood pressure (BP), LDL cholesterol, accordance with CCM (assessed by Patient Assessment of Chronic Illness Care [PACIC] questionnaire), and quality of life (assessed by the 36-item short-form health survey [SF-36]). RESULTS After 1 year, HbA1c levels decreased significantly in both groups with no significant difference between groups (−0.05% [−0.60 mmol/mol]; P = 0.708). Among intervention group patients, systolic BP (−3.63; P = 0.050), diastolic BP (−4.01; P < 0.001), LDL cholesterol (−0.21; P = 0.033), and PACIC subscores (P < 0.001 to 0.048) significantly improved compared with control group patients. No differences between groups were shown in the SF-36 subscales. CONCLUSIONS A chronic care approach according to the CCM and involving practice nurses in diabetes care improved the cardiovascular risk profile and is experienced by patients as a better structured care. Our study showed that care according to the CCM can be implemented even in small primary care practices, which still represent the usual structure in most European health care systems.


Journal of Evaluation in Clinical Practice | 2012

The German version of the Assessment of Chronic Illness Care: instrument translation and cultural adaptation.

Claudia Steurer-Stey; Anja Frei; Gabriela Schmid‐Mohler; Sibylle Malcolm‐Kohler; Marco Zoller; Thomas Rosemann

BACKGROUND In Switzerland, there is a dearth of information on the extent to which patients with chronic illnesses receive care congruent with the Chronic Care Model (CCM). To drive quality improvement programmes, it is necessary to have practical assessment tools in the countrys own language to evaluate the delivery of CCM activities. METHODS German translation and adaptation of the original Assessment of Chronic Illness Care (ACIC). We followed a sequential forward and backward translation approach. In a multidisciplinary committee review the original English version and the translations were compared, instructions and formats modified and cross-cultural equivalences verified. The second version was pre-tested and multidisciplinary group discussion led to the final version which aimed to create a comprehensive culturally adapted translation capturing the original idea of the items rather than a direct one to one translation. RESULTS Difficulties encountered during the translation process consisted in the difference of health care settings and health care organization in Switzerland and USA.The adapted German version was delivered to a managed care organization in the city of Zurich to test the initial use for diabetes care. The average ACIC subscale scores were: organization of the health care delivery system: mean (m) = 7.31 (SD = 0.79), community linkages: m = 3.78 (SD = 1.09), self-management support: m = 4.88 (SD = 1.21), decision support: m = 4.79 (SD = 1.16), delivery system design: m = 5.56 (SD = 1.28) and clinical information systems: m = 4.50 (SD = 2.69). Overall, the ACIC subscale scores were comparable with the scores of the original testing. CONCLUSION After cultural adaptations the German version of the ACIC is applicable as a tool to guide quality improvement in chronic illness care in German speaking countries in Europe.


European Respiratory Journal | 2017

A multicentre validation of the 1-min sit-to-stand test in patients with COPD.

Sarah Crook; Gilbert Büsching; K Schultz; Nicola Lehbert; D Jelusic; Stephan Keusch; M Wittmann; Michael Schuler; Thomas Radtke; Martin Frey; Alexander Turk; Milo A. Puhan; Anja Frei

Our aim was to comprehensively validate the 1-min sit-to-stand (STS) test in chronic obstructive pulmonary disease (COPD) patients and explore the physiological response to the test. We used data from two longitudinal studies of COPD patients who completed inpatient pulmonary rehabilitation programmes. We collected 1-min STS test, 6-min walk test (6MWT), health-related quality of life, dyspnoea and exercise cardiorespiratory data at admission and discharge. We assessed the learning effect, test–retest reliability, construct validity, responsiveness and minimal important difference of the 1-min STS test. In both studies (n=52 and n=203) the 1-min STS test was strongly correlated with the 6MWT at admission (r=0.59 and 0.64, respectively) and discharge (r=0.67 and 0.68, respectively). Intraclass correlation coefficients (95% CI) between 1-min STS tests were 0.93 (0.83–0.97) for learning effect and 0.99 (0.97–1.00) for reliability. Standardised response means (95% CI) were 0.87 (0.58–1.16) and 0.91 (0.78–1.07). The estimated minimal important difference was three repetitions. End-exercise oxygen consumption, carbon dioxide output, ventilation, breathing frequency and heart rate were similar in the 1-min STS test and 6MWT. The 1-min STS test is a reliable, valid and responsive test for measuring functional exercise capacity in COPD patients and elicited a physiological response comparable to that of the 6MWT. The 1-min STS test is a reliable, valid and responsive exercise capacity test in COPD with an MID of 3 repetitions http://ow.ly/teNx307ni0Q

Collaboration


Dive into the Anja Frei's collaboration.

Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar

Tsung Yu

University of Zurich

View shared research outputs
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar

Thierry Troosters

Katholieke Universiteit Leuven

View shared research outputs
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Researchain Logo
Decentralizing Knowledge