G. ter Riet

A systematic review of the clinical effectiveness of orlistat used for the management of obesity

The aim of this paper is to assess the clinical effectiveness of orlistat used for the management of obesity. Nineteen electronic databases were searched for randomized controlled trials evaluating the effectiveness of orlistat for weight loss or maintenance of weight loss in overweight or obese patients. Each included trial was assessed for methodological quality. Statistical pooling was performed when trials were considered to be sufficiently similar. Twenty‐three trials were eligible for inclusion. Placebo‐controlled trials recruiting patients with uncomplicated obesity reported statistically significant differences in favour of orlistat for weight loss and changes in obesity‐related risk factors at all time points. Trials in obese patients with defined risk factors at baseline showed similar results, however, smaller effect sizes were observed in patients with type 2 diabetes. The effectiveness of orlistat relative to other anti‐obesity drugs is currently unclear. When orlistat was added to simvastatin, this proved to be more effective for weight loss than either drug used individually. Orlistat use is associated with a higher incidence of gastrointestinal adverse events compared with placebo. In conclusion, orlistat is more effective than placebo in promoting weight loss, maintenance of weight loss, and improving cardiovascular risk factor profiles. Baseline parameters of patients seen in clinical practice should be taken into account when considering treatment.

Systematic reviews and meta-analyses of preclinical studies: publication bias in laboratory animal experiments

In 2006, Peters et al. identified 86 systematic reviews (SRs) of laboratory animal experiments (LAEs). They found 46 LAE meta-analyses (MAs), often of poor quality. Six of these 46 MAs tried to assess publication bias. Publication bias is the phenomenon of an experiments results determining its likelihood of publication, often over-representing positive findings. As such, publication bias is the Achilles heel of any SR. Since researchers increasingly become aware of the fact that SRs directly support the ‘three Rs’, we expect the number of SRs of LAEs will sharply increase. Therefore, it is useful to see how publication bias is dealt with. Our objective was to identify all SRs and MAs of LAEs where the purpose was to inform human health published between July 2005 and 2010 with special attention to MAs’ quality features and publication bias. We systematically searched Medline, Embase, Toxline and ScienceDirect from July 2005 to 2010, updating Peters’ review. LAEs not directly informing human health or concerning fundamental biology were excluded. We found 2780 references of which 163 met the inclusion criteria: 158 SRs, of which 30 performed an MA, and five MAs without an SR. The number of SRs roughly doubled every three years since 1997. The number of MAs roughly doubled every five years since 1999. Compared with before July 2005, more MAs were preceded by SR and reported on (quality) features of included studies and heterogeneity. A statistically significant proportion of MAs considered publication bias (26/35) and tried to formally assess it (21 /35).

Smoking cessation after an acute coronary syndrome: immediate quitters are successful quitters.

BackgroundCardiovascular disease (CVD) prevention guidelines stress the importance of smoking cessation and recommend intensive follow-up. To guide the development of such cessation support strategies, we analysed the characteristics that are associated with successful smoking cessation after an acute coronary syndrome (ACS).MethodsWe used data from the Randomised Evaluation of Secondary Prevention for ACS patients coordinated by Outpatient Nurse SpEcialists (RESPONSE) trial (n = 754). This was designed to quantify the impact of a nurse-coordinated prevention program, focusing on healthy lifestyles, traditional CVD risk factors and medication adherence. For the current analysis we included all smokers (324/754, 43 %). Successful quitters were defined as those who reported abstinence at 1 year of follow-up.ResultsThe majority of successful quitters quit immediately after the ACS event and remained abstinent through 1 year of follow-up, without extra support (128/156, 82 %). Higher education level (33 vs. 15 %, p < 0.01), no history of CVD (87 vs. 74 %, p < 0.01) and being on target for LDL-cholesterol level at 1 year (78 vs. 63 %, p < 0.01) were associated with successful quitting.ConclusionThe majority of successful quitters at 1 year stopped immediately after their ACS. Patients in this group showed that it was within their own ability to quit, and they did not relapse through 1 year of follow-up. Our study indicates that in a large group of patients who quit immediately after a life-threatening event, no relapse prevention program is needed.

Prevalence of mild cognitive impairment and dementia in older non-western immigrants in the Netherlands: a cross-sectional study

In the Netherlands, persons of Turkish, Moroccan and Surinamese descent form the largest groups of non‐western immigrants. A high prevalence of mild cognitive impairment (MCI) and dementia has been described in immigrant populations in the United States of America and the United Kingdom. We determined the prevalence of MCI and dementia in older community‐dwelling adults from the largest non‐western immigrant groups in the Netherlands.

COPD: more than respiratory

1 Patel A; ADVANCE Collaborative Group. Eff ect of a fi xed combination of perindopril and indapamide on macrovascular and microvascular outcomes in patients with type 2 diabetes mellitus (the ADVANCE trial): a randomised controlled trial. Lancet 2007; 370: 829–40. 2 PROGRESS Collaborative Group. Randomised trial of a perindopril-based blood-pressure lowering regimen among 6105 individuals with previous stroke or transient ischaemic attack. Lancet 2001; 358: 1033–41.

Prediction models in obstetrics: understanding the treatment paradox and potential solutions to the threat it poses

the treatment paradox and potential solutions to the threat it poses F Cheong-See, J Allotey, N Marlin, BW Mol, E Schuit, G ter Riet, RD Riley, KGM Moons, KS Khan, S Thangaratinam a Women’s Health Research Unit, Barts and the London School of Medicine and Dentistry, Blizard Institute, Queen Mary University London, London, UK b Multidisciplinary Evidence Synthesis Hub (MESH), Queen Mary University of London, UK c Pragmatic Clinical Trials Unit, Barts and the London School of Medicine and Dentistry, Blizard Institute, Queen Mary University London, London, UK d Australian Research Centre for Health of Women and Babies, Robinson Institute, The University of Adelaide, Adelaide, SA, Australia e Julius Centre for Health Sciences and Primary Care, University Medical Centre Utrecht, Utrecht, the Netherlands f Stanford Prevention Research Center, Stanford University, Stanford, CA, USA g Department of General Practice, Academic Medical Center, University of Amsterdam, Amsterdam, the Netherlands h Research Institute for Primary Care and Health Sciences, Keele University, Staffordshire, UK Correspondence: Prof S Thangaratinam, Women’s Health Research Unit, Barts and the London School of Medicine and Dentistry, Queen Mary University London, Yvonne Carter Building, 58 Turner Street, London E1 2AB, UK. Email s.thangaratinam@qmul.ac.uk

Diagnosis of conjunctivitis in primary care: comparison of two different culture procedures.

Background: In general practice, infectious conjunctivitis is a common and mostly (64%) self-limiting disorder. In case of an aberrant course or severe symptoms, a general practitioner may take a culture. Direct inoculation is considered the reference standard, but usually a swab is sent to a laboratory. Objectives: To compare the diagnostic performance of the swab, transported by surface mail with direct inoculation. Methods: 19 general practitioners took two samples of the conjunctiva from 88 patients with symptoms suggestive of infectious conjunctivitis by rolling a cotton swab across the conjunctiva of the lower fornix. One swab was used to inoculate three agar plates directly, while the other was sent in a Stuart medium to the laboratory and inoculated at the time of arrival. The numbers of positive cultures of both methods were compared. Results: A pathogen was found in 31 of 88 samples (35% (95% CI 26 to 46)). Surprisingly, the number of positive cultures was higher for the Stuart medium (27/88) than for direct inoculation (23/88). The difference was 4.5% (90% CI 0 to 12, p = 0.388; one-sided McNemar test for paired proportions). In five of the 19 samples that were positive in both tests, the cultured pathogens were different. Conclusions: The Stuart medium detected more bacteria than direct inoculation. The lower 90% CI, testing non-inferiority at p = 0.05, indicates that it is unlikely that the Stuart medium misses any positive cultures compared with direct inoculation.

De invloed van presentatiewijze van diagnostische testuitslagen op ziektekansschattingen van huisartsenevidence based medicineNHG-wetenschapsdag

SamenvattingInleiding Dagelijks beoordeelt de huisarts resultaten van diagnostische tests.

Minimal important change and minimal detectable change in activities of daily living in community-living older people

ObjectiveTo estimate the minimal important change (MIC) and the minimal detectable change (MDC) of the Katz-activities of daily living (ADL) index score and the Lawton instrumental activities of daily living (IADL) scale.DesignData from a cluster-randomized clinical trial and a cohort study.SettingGeneral practices in the Netherlands.Participants3184 trial participants and 51 participants of the cohort study with a mean age of 80.1 (SD 6.4) years.MeasurementsAt baseline and after 6 months, the Katz-ADL index score (0-6 points), the Lawton IADL scale (0-7 points), and self-perceived decline in (I)ADL were assessed using a self-reporting questionnaire. MIC was assessed using anchor-based methods: the (relative) mean change score; and using distributional methods: the effect size (ES), the standard error of measurement (SEM), and 0.5 SD. The MDC was estimated using SEM, based on a test-retest study (2-week interval) and on the anchor-based method.ResultsAnchor-based MICs of the Katz-ADL index score were 0.47 points, while distributional MICs ranged from 0.18 to 0.47 points. Similarly, anchor-based MICs of the Lawton IADL scale were between 0.31 and 0.54 points and distributional MICs ranged from 0.31 to 0.77 points. The MDC varies by sample size. For the MIC to exceed the MDC at least 482 patients are needed.ConclusionThe MIC of both the Katz-ADL index and the Lawton IADL scale lie around half a point. The certainty of this conclusion is reduced by the variation across calculational methods.

Betekenis van klachten en symptomen voor de diagnostiek van acute infectieuze conjunctivitis: een systematisch literatuuronderzoek

SamenvattingRietveld RP, Van Weert HCPM, Ter Riet G, Bindels PJE. Betekenis van klachten en symptomen voor de diagnostiek van acute infectieuze conjunctivitis: een systematisch literatuuronderzoek. Huisarts Wet 2004;47(5):227-9.Inleiding Om bij een ‘pusoog’ selectiever antibiotica te kunnen voorschrijven, moet men een bacteriële van een virale conjunctivitis kunnen onderscheiden. Klachten en symptomen, zoals purulente afscheiding, worden verondersteld van diagnostische betekenis te zijn voor de oorzaak van acute infectieuze conjunctivitis. Wij doorzochten de literatuur naar bewijzen voor deze veronderstellingen.Methoden In PubMed, Embase, CINAHL, het Cochrane Controlled Trial Register, de literatuurlijst van de NHG-Standaard Het rode oog en van oogheelkundige leerboeken werd gezocht naar relevante artikelen. Wij sloten artikelen in waarin klachten of symptomen werden vergeleken met het resultaat van een bacteriële kweek.Resultaten Wij vonden geen artikelen waarin de betekenis van klachten en symptomen voor het onderscheid tussen een virale en bacteriële conjunctivitis werd onderzocht.Beschouwing Er is geen bewijs dat de huidige diagnostische criteria bruikbaar zijn voor het onderscheid tussen een virale en bacteriële conjunctivitis. Diagnostisch onderzoek is nodig om selectiever antibiotica voor te kunnen schrijven.Dit artikel is een bewerking van: Rietveld RP, Van Weert HCPM, Ter Riet G, Bindels PJE. Diagnostic impact of signs and symptoms in acute infectious conjunctivitis: systematic literature search (BMJ 2003;327:789). Publicatie gebeurt met toestemming van de uitgever.