Analyzing the content of outcome measures in clinical trials on irritable bowel syndrome using the international classification of functioning, disability and health as a reference.
ABSTRACT Patients with irritable bowel syndrome (IBS) report a significant impact of their symptoms on functional health. In outcome assessment of clinical studies on IBS, however, functional aspects other than gastrointestinal symptoms seem to be disregarded to a great extent.
To analyze the content of outcome measures used in clinical IBS trials.
A systematic review was performed in terms of a quantitative content analysis using the International Classification of Functioning, Disability and Health (ICF) as a coding scheme. Outcome measures were selected from all randomized controlled trials on IBS published in PubMed from the beginning to April 2002. From the outcome measures pre-specified text passages, so-called coding units, were extracted and linked to the ICF. A coding unit had to describe a single health aspect or an internal or external factor with an impact on health. If the outcome measure was a test the goal of the test was semantically implicated. Only second-level ICF categories contained in the outcome assessment of at least 10 % of the studies were considered. All steps of the review were performed by three independent raters.
99 studies were included. Single items were used as outcome measures in 88, clinical and paraclinical tests in 42 and questionnaires in 24 studies. Ninety percent of the coding units (n = 2271) could be linked to the ICF. ICF categories describing gastrointestinal symptoms were considered in the outcome assessment of 37 to 85 studies depending on the type of content compared to extra-gastrointestinal symptoms in 10 to 22 studies. Health information of ICF components other than "body functions" was scarcely included. Clear secular trends for individual ICF categories could not be found. Only a single IBS-specific questionnaire considered health information other than gastrointestinal symptoms.
Outcome assessment of clinical IBS studies is mainly based on gastrointestinal symptoms. The assessment of other health aspects like comorbid psychological symptoms or social consequences of the disease seems to be similarly important and should be considered in future trials. This would also facilitate the understanding of IBS as a biopsychosocial health condition, both in matters of aetiology and consequences.
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ABSTRACT: In 1976, the World Health Organization (WHO) estimated worldwide disability prevalence at 10%; recent evidence suggests the prevalence is even higher. Given the extent of disability around the world, it is essential for researchers and policy makers to have a uniform language for describing and discussing disability. The International Classification of Functioning, Disability and Health (ICF) is WHO's attempt to provide that standard language. Linking rules were published in 2002 and 2005 suggesting a method for standardising the process of connecting outcome measures to the ICF classification. The objective of this study is to study the extent to which the linking rules have been used by researchers to link health and health-related information to the ICF and collect the feedback about the current practices, applications and areas to improve the linking method. Using a systematic review of health-based literature between 2001 and February 2008, we (1) determined research areas where the linking method is applied, (2) examined the characteristics of studies that linked information to the ICF and (3) described current practices and issues related to the process of linking health and health-related information to the ICF both quantitatively and qualitatively. The systematic review yielded 109 articles from 58 journals that linked health information to the ICF and 58 of the articles employed published linking rules. The majority of articles were descriptive in nature, used linking for connecting content of health instruments to the ICF and linked English health content. Quality controls such as reliability checks, multiple raters and iterative linking processes were found frequently among users of the linking rules. Qualitative analysis created themes about: preparing units of information, who links to the ICF, reliability, matching or translating concepts from text to ICF categories, information unable or difficult to capture, quantitative reporting standards and overall linking process. This review also shows that the linking process is a useful way to apply the ICF classification in research. With over 100 articles published in 58 peer-reviewed journals across 50 focus areas, linking health and health-related information to the ICF has been shown to be a useful tool for describing, comparing and contrasting information from outcome measures used to collect quantitative data, qualitative research results and clinical patient reports across diagnoses, settings, languages and countries.Disability and Rehabilitation 02/2011; 33(21-22):1941-51. DOI:10.3109/09638288.2011.553704 · 1.84 Impact Factor
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ABSTRACT: To present a systematic literature review on the state of the art of the utilisation of the International Classification of Functioning, Disability and Health (ICF) since its release in 2001. The search was conducted through EMBASE, MEDLINE and PsychInfo covering the period between 2001 and December 2009. Papers were included if ICF was mentioned in title or abstract. Papers focussing on the ICF-CY and clinical research on children and youth only were excluded. Papers were assigned to six different groups covering the wide scenario of ICF application. A total of 672 papers, coming from 34 countries and 211 different journals, were included in the analysis. The majority of publications (30.8%) were conceptual papers or papers reporting clinical and rehabilitation studies (25.9%). One-third of the papers were published in 2008 and 2009. The ICF contributed to the development of research on functioning and on disability in clinical, rehabilitation as well as in several other contexts, such as disability eligibility and employment. Diffusion of ICF research and use in a great variety of fields and scientific journals is a proof that a cultural change and a new conceptualisation of functioning and disability is happening.Disability and Rehabilitation 11/2010; 33(4):281-309. DOI:10.3109/09638288.2010.529235 · 1.84 Impact Factor
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ABSTRACT: To investigate the pharmacological effect of TongXie-YaoFang (TXYF) formula and its underlying mechanisms. A neonatal maternal separation plus restraint stress (NMS + RS) model of diarrhea-predominant irritable bowel syndrome was developed by subjecting male Sprague-Dawley rats to daily maternal separation from postnatal days 2 to 21 plus restraint stress from days 50 to 59. Rats were randomly divided into two groups (NMS + RS and TXYF formula), and rats with no handling or separation were used as normal controls. Starting from postnatal day 60, rats were administered TXYF formula (9.84 g/100 g body weight) orally twice daily for 14 consecutive days, while the normal and NMS + RS groups were given distilled water. The distinctions of movement index (MI, area under the curve of contraction intensity/min, mg/min) and contraction frequency (CF, number of contractions/min, times/min) of isolated colonic longitudinal smooth muscle strips (CLSMs) in the three groups before and after treatment were observed with a Power Lab system. Different inhibitors were applied, and then 10(-4) mol/L acetylcholine chloride (Ach) was added to CLSMs to induce muscle contraction. Before treatment, the MI of CLSMs in the NMS + RS and TXYF formula groups was similar and both higher than that in the normal group (545.49 ± 73.66 mg/min vs 245.76 ± 34.44 mg/min and 551.09 ± 54.29 mg/min vs 245.76 ± 34.44 mg/min, P < 0.01, respectively). After treatment, the MI in the TXYF formula group was lower than that in the NMS + RS group (261.39 ± 38.59 mg/min vs 533.9 ± 61.63 mg/min, P < 0.01). In the same way, the CF of CLSMs in the NMS + RS and TXYF formula groups was similar and both higher than that in the normal group (3.42 ± 0.25 times/min and 3.31 ± 0.21 vs 1.1 ± 0.17 times/min, P < 0.01) before treatment. After treatment, the CF in the TXYF formula group was lower than that in the NMS + RS group (1.42 ± 0.87 times/min vs 3.11 ± 0.82 times/min, P < 0.01) and similar to that in the normal group (1.42 ± 0.87 times/min vs 1.09 ± 0.13 times/min). When 8-(N,N-diethylamino)octyl 3,4,5-trimethoxybenzoate hydrochloride and 4-aminopyridine were added to the bath and equilibrated for 30 min, respectively, and 10(-4) mol/L Ach was added to CLSMs to induce muscle contraction, MI of the CLSMs in the TXYF formula group was lower than that in the normal group (666 ± 36.32 mg/min vs 747.77 ± 49.47 mg/min, and 686.53 ± 39.17 mg/min vs 750.45 ± 29.39 mg/min; P < 0.01, respectively). The MI of CLSMs in the TXYF formula group was lower than that in the normal group after treatment with nifedipine (689.48 ± 30.84 mg/min vs 741.65 ± 32.41 mg/min; P < 0.05). TXYF formula inhibits colon contraction in rats. This may be related to activation of specific potassium channels and inhibition of extracellular calcium internal flow.