A methodological survey of the analysis, reporting and interpretation of Absolute Risk ReductiOn in systematic revieWs (ARROW): a study protocol

BACKGROUND

Clinicians, providers and guideline panels use absolute effects to weigh the advantages and downsides of treatment alternatives. Relative measures have the potential to mislead readers. However, little is known about the reporting of absolute measures in systematic reviews. The objectives of our study are to determine the proportion of systematic reviews that report absolute measures of effect for the most important outcomes, and ascertain how they are analyzed, reported and interpreted.

METHODS/DESIGN

We will conduct a methodological survey of systematic reviews published in 2010. We will conduct a 1:1 stratified random sampling of Cochrane vs. non-Cochrane systematic reviews. We will calculate the proportion of systematic reviews reporting at least one absolute estimate of effect for the most patient-important outcome for the comparison of interest. We will conduct multivariable logistic regression analyses with the reporting of an absolute estimate of effect as the dependent variable and pre-specified study characteristics as the independent variables. For systematic reviews reporting an absolute estimate of effect, we will document the methods used for the analysis, reporting and interpretation of the absolute estimate.

DISCUSSION

Our methodological survey will inform current practices regarding reporting of absolute estimates in systematic reviews. Our findings may influence recommendations on reporting, conduct and interpretation of absolute estimates. Our results are likely to be of interest to systematic review authors, funding agencies, clinicians, guideline developers and journal editors.

Probiotics for the prevention of Clostridium difficile-associated diarrhea in adults and children

BACKGROUND

Antibiotics are widely prescribed; however they can cause disturbances in gastrointestinal flora which may lead to reduced resistance to pathogens such as Clostridium difficile (C. difficile). Probiotics are live organisms thought to balance the gastrointestinal flora.

OBJECTIVES

The primary objectives were to assess the efficacy and safety of probiotics for preventing Clostridium difficile-associated diarrhea (CDAD) or C. difficile infection in adults and children.

SEARCH METHODS

On February 21, 2013 we searched PubMed (1966-2013), EMBASE (1966-2013), Cochrane Central Register of Controlled Trials (The Cochrane Library 2013, Issue 1), CINAHL (1982-2013), AMED (1985-2013), and ISI Web of Science. Additionally, we conducted an extensive grey literature search including contact with industry representatives.

SELECTION CRITERIA

Randomized controlled (placebo, alternative prophylaxis, or no treatment control) trials investigating probiotics (any strain, any dose) for prevention of CDAD, or C. difficile infection were considered for inclusion.

DATA COLLECTION AND ANALYSIS

Two authors independently and in duplicate extracted data and assessed risk of bias using pre-constructed, and piloted, data extraction forms. Any disagreements were resolved by a third adjudicator. For articles published in abstract form only, further information was sought by contacting principal authors. The primary outcome was the incidence of CDAD. Secondary outcomes included the incidence of C. difficile infection, adverse events, antibiotic-associated diarrhea (AAD) and length of hospital stay. Dichotomous outcomes (e.g. incidence of CDAD) were pooled using a random-effects model to calculate the relative risk and corresponding 95% confidence interval (95% CI). Continuous outcomes (e.g. length of hospital) were pooled using a random-effects model to calculate the mean difference and corresponding 95% CI. Sensitivity analyses were conducted to explore the impact of missing data on efficacy and safety outcomes. For the sensitivity analyses, we assumed that the event rate for those participants in the control group who had missing data was the same as the event rate for those participants in the control group who were successfully followed. For the probiotic group we calculated effects using the following assumed ratios of event rates in those with missing data in comparison to those successfully followed: 1.5:1, 2:1, 3:1, and 5:1. To explore possible explanations for heterogeneity, a priori subgroup analysis were conducted on probiotic species, dose, adult versus pediatric population, and risk of bias.The overall quality of the evidence supporting each outcome was assessed using the GRADE criteria.

MAIN RESULTS

A total of 1871 studies were identified with 31 (4492 participants) meeting eligibility requirements for our review. Overall 11 studies were rated as a high risk of bias due mostly to missing outcome data. A complete case analysis (i.e. participants who completed the study) of those trials investigating CDAD (23 trials, 4213 participants) suggests that probiotics significantly reduce this risk by 64%. The incidence of CDAD was 2.0% in the probiotic group compared to 5.5% in the placebo or no treatment control group (RR 0.36; 95% CI 0.26 to 0.51). Sixteen of 23 trials had missing CDAD data ranging from 5% to 45%. These results proved robust to sensitivity analyses of plausible and worst-plausible assumptions regarding missing outcome data and were similar whether considering trials in adults versus children, lower versus higher doses, different probiotic species, or higher versus lower risk of bias. Our judgment is that the overall evidence warrants moderate confidence in this large relative risk reduction. We downgraded the overall quality of evidence for CDAD to 'moderate' due to imprecision. There were few events (154) and the calculated optimal information size (n = 8218) was more than the total sample size. With respect to the incidence of C. difficile infection, a secondary outcome, pooled complete case results from 13 trials (961 participants) did not show a statistically significant reduction. The incidence of C. difficile infection was 12.6% in the probiotics group compared to 12.7% in the placebo or no treatment control group (RR 0.89; 95% CI 0.64 to 1.24). Adverse events were assessed in 26 studies (3964 participants) and our pooled complete case analysis indicates probiotics reduce the risk of adverse events by 20% (RR 0.80; 95% CI 0.68 to 0.95). In both treatment and control groups the most common adverse events included abdominal cramping, nausea, fever, soft stools, flatulence, and taste disturbance. For the short-term use of probiotics in patients that are not immunocompromised or severely debilitated, we consider the strength of this evidence to be moderate.

AUTHORS' CONCLUSIONS

Based on this systematic review and meta-analysis of 23 randomized controlled trials including 4213 patients, moderate quality evidence suggests that probiotics are both safe and effective for preventing Clostridium difficile-associated diarrhea.

Probiotics for the prevention of Clostridium difficile-associated diarrhea in adults and children

BACKGROUND

Antibiotics are widely prescribed; however they can cause disturbances in gastrointestinal flora which may lead to reduced resistance to pathogens such as Clostridium difficile (C. difficile). Probiotics are live organisms thought to balance the gastrointestinal flora.

OBJECTIVES

The primary objectives were to assess the efficacy and safety of probiotics for preventing Clostridium difficile-associated diarrhea (CDAD) or C. difficile infection in adults and children.

SEARCH METHODS

On February 21, 2013 we searched PubMed (1966-2013), EMBASE (1966-2013), Cochrane Central Register of Controlled Trials (The Cochrane Library 2013, Issue 1), CINAHL (1982-2013), AMED (1985-2013), and ISI Web of Science. Additionally, we conducted an extensive grey literature search including contact with industry representatives.

SELECTION CRITERIA

Randomized controlled (placebo, alternative prophylaxis, or no treatment control) trials investigating probiotics (any strain, any dose) for prevention of CDAD, or C. difficile infection were considered for inclusion.

DATA COLLECTION AND ANALYSIS

Two authors independently and in duplicate extracted data and assessed risk of bias using pre-constructed, and piloted, data extraction forms. Any disagreements were resolved by a third adjudicator. For articles published in abstract form only, further information was sought by contacting principal authors. The primary outcome was the incidence of CDAD. Secondary outcomes included the incidence of C. difficile infection, adverse events, antibiotic-associated diarrhea (AAD) and length of hospital stay. Dichotomous outcomes (e.g. incidence of CDAD) were pooled using a random-effects model to calculate the relative risk and corresponding 95% confidence interval (95% CI). Continuous outcomes (e.g. length of hospital) were pooled using a random-effects model to calculate the mean difference and corresponding 95% CI. Sensitivity analyses were conducted to explore the impact of missing data on efficacy and safety outcomes. For the sensitivity analyses, we assumed that the event rate for those participants in the control group who had missing data was the same as the event rate for those participants in the control group who were successfully followed. For the probiotic group we calculated effects using the following assumed ratios of event rates in those with missing data in comparison to those successfully followed: 1.5:1, 2:1, 3:1, and 5:1. To explore possible explanations for heterogeneity, a priori subgroup analysis were conducted on probiotic species, dose, adult versus pediatric population, and risk of bias.The overall quality of the evidence supporting each outcome was assessed using the GRADE criteria.

MAIN RESULTS

A total of 1871 studies were identified with 31 (4492 participants) meeting eligibility requirements for our review. Overall 11 studies were rated as a high risk of bias due mostly to missing outcome data. A complete case analysis (i.e. participants who completed the study) of those trials investigating CDAD (23 trials, 4213 participants) suggests that probiotics significantly reduce this risk by 64%. The incidence of CDAD was 2.0% in the probiotic group compared to 5.5% in the placebo or no treatment control group (RR 0.36; 95% CI 0.26 to 0.51). Sixteen of 23 trials had missing CDAD data ranging from 5% to 45%. These results proved robust to sensitivity analyses of plausible and worst-plausible assumptions regarding missing outcome data and were similar whether considering trials in adults versus children, lower versus higher doses, different probiotic species, or higher versus lower risk of bias. Our judgment is that the overall evidence warrants moderate confidence in this large relative risk reduction. We downgraded the overall quality of evidence for CDAD to 'moderate' due to imprecision. There were few events (154) and the calculated optimal information size (n = 8218) was more than the total sample size. With respect to the incidence of C. difficile infection, a secondary outcome, pooled complete case results from 13 trials (961 participants) did not show a statistically significant reduction. The incidence of C. difficile infection was 12.6% in the probiotics group compared to 12.7% in the placebo or no treatment control group (RR 0.89; 95% CI 0.64 to 1.24). Adverse events were assessed in 26 studies (3964 participants) and our pooled complete case analysis indicates probiotics reduce the risk of adverse events by 20% (RR 0.80; 95% CI 0.68 to 0.95). In both treatment and control groups the most common adverse events included abdominal cramping, nausea, fever, soft stools, flatulence, and taste disturbance. For the short-term use of probiotics in patients that are not immunocompromised or severely debilitated, we consider the strength of this evidence to be moderate.

AUTHORS' CONCLUSIONS

Based on this systematic review and meta-analysis of 23 randomized controlled trials including 4213 patients, moderate quality evidence suggests that probiotics are both safe and effective for preventing Clostridium difficile-associated diarrhea.

Probiotics for the prevention of Clostridium difficile-associated diarrhea: a systematic review and meta-analysis

BACKGROUND

Antibiotic treatment may disturb the resistance of gastrointestinal flora to colonization. This may result in complications, the most serious of which is Clostridium difficile–associated diarrhea (CDAD).

PURPOSE

To assess the efficacy and safety of probiotics for the prevention of CDAD in adults and children receiving antibiotics.

DATA SOURCES

Cochrane Central Register of Controlled Trials, MEDLINE, EMBASE, CINAHL, Allied and Complementary Medicine Database, Web of Science, and 12 gray-literature sources.

STUDY SELECTION

Randomized, controlled trials including adult or pediatric patients receiving antibiotics that compared any strain or dose of a specified probiotic with placebo or with no treatment control and reported the incidence of CDAD.

DATA EXTRACTION

Two reviewers independently screened potentially eligible articles; extracted data on populations, interventions, and outcomes; and assessed risk of bias. The Grading of Recommendations Assessment, Development and Evaluation guidelines were used to independently rate overall confidence in effect estimates for each outcome.

DATA SYNTHESIS

Twenty trials including 3818 participants met the eligibility criteria. Probiotics reduced the incidence of CDAD by 66% (pooled relative risk, 0.34 [95% CI, 0.24 to 0.49]; I(2) = 0%). In a population with a 5% incidence of antibiotic-associated CDAD (median control group risk), probiotic prophylaxis would prevent 33 episodes (CI, 25 to 38 episodes) per 1000 persons. Of probiotic-treated patients, 9.3% experienced adverse events, compared with 12.6% of control patients (relative risk, 0.82 [CI, 0.65 to 1.05]; I(2) = 17%).

LIMITATIONS

In 13 trials, data on CDAD were missing for 5% to 45% of patients. The results were robust to worst-plausible assumptions regarding event rates in studies with missing outcome data.

CONCLUSION

Moderate-quality evidence suggests that probiotic prophylaxis results in a large reduction in CDAD without an increase in clinically important adverse events.

PRIMARY FUNDING SOURCE

None.

Learning from failure--rationale and design for a study about discontinuation of randomized trials (DISCO study)

BACKGROUND

Randomized controlled trials (RCTs) may be discontinued because of apparent harm, benefit, or futility. Other RCTs are discontinued early because of insufficient recruitment. Trial discontinuation has ethical implications, because participants consent on the premise of contributing to new medical knowledge, Research Ethics Committees (RECs) spend considerable effort reviewing study protocols, and limited resources for conducting research are wasted. Currently, little is known regarding the frequency and characteristics of discontinued RCTs.

METHODS/DESIGN

Our aims are, first, to determine the prevalence of RCT discontinuation for specific reasons; second, to determine whether the risk of RCT discontinuation for specific reasons differs between investigator- and industry-initiated RCTs; third, to identify risk factors for RCT discontinuation due to insufficient recruitment; fourth, to determine at what stage RCTs are discontinued; and fifth, to examine the publication history of discontinued RCTs.We are currently assembling a multicenter cohort of RCTs based on protocols approved between 2000 and 2002/3 by 6 RECs in Switzerland, Germany, and Canada. We are extracting data on RCT characteristics and planned recruitment for all included protocols. Completion and publication status is determined using information from correspondence between investigators and RECs, publications identified through literature searches, or by contacting the investigators. We will use multivariable regression models to identify risk factors for trial discontinuation due to insufficient recruitment. We aim to include over 1000 RCTs of which an anticipated 150 will have been discontinued due to insufficient recruitment.

DISCUSSION

Our study will provide insights into the prevalence and characteristics of RCTs that were discontinued. Effective recruitment strategies and the anticipation of problems are key issues in the planning and evaluation of trials by investigators, Clinical Trial Units, RECs and funding agencies. Identification and modification of barriers to successful study completion at an early stage could help to reduce the risk of trial discontinuation, save limited resources, and enable RCTs to better meet their ethical requirements.

Probiotics for the prevention of pediatric antibiotic-associated diarrhea

BACKGROUND

Antibiotics alter the microbial balance within the gastrointestinal tract. Probiotics may prevent antibiotic-associated diarrhea (AAD) via restoration of the gut microflora. Antibiotics are prescribed frequently in children and AAD is common in this population.

OBJECTIVES

The primary objectives were to assess the efficacy and safety of probiotics (any specified strain or dose) used for the prevention of AAD in children.

SEARCH METHODS

MEDLINE, EMBASE, CENTRAL, CINAHL, AMED, and the Web of Science (inception to May 2010) were searched along with specialized registers including the Cochrane IBD/FBD review group, CISCOM (Centralized Information Service for Complementary Medicine), NHS Evidence, the International Bibliographic Information on Dietary Supplements as well as trial registries. Letters were sent to authors of included trials, nutra/pharmaceutical companies, and experts in the field requesting additional information on ongoing or unpublished trials. Conference proceedings, dissertation abstracts, and reference lists from included and relevant articles were also searched.

SELECTION CRITERIA

Randomized, parallel, controlled trials in children (0 to 18 years) receiving antibiotics, that compare probiotics to placebo, active alternative prophylaxis, or no treatment and measure the incidence of diarrhea secondary to antibiotic use were considered for inclusion.

DATA COLLECTION AND ANALYSIS

Study selection, data extraction as well as methodological quality assessment using the risk of bias instrument was conducted independently and in duplicate by two authors. Dichotomous data (incidence of diarrhea, adverse events) were combined using a pooled relative risk and risk difference (adverse events), and continuous data (mean duration of diarrhea, mean daily stool frequency) as weighted mean differences, along with their corresponding 95% confidence intervals. For overall pooled results on the incidence of diarrhea, sensitivity analyses included available case versus extreme-plausible analyses and random- versus fixed-effect models. To explore possible explanations for heterogeneity, a priori subgroup analysis were conducted on probiotic strain, dose, definition of antibiotic-associated diarrhea, antibiotic agent as well as risk of bias.

MAIN RESULTS

Sixteen studies (3432 participants) met the inclusion criteria. Trials included treatment with either Bacillus spp., Bifidobacterium spp., Lactobacilli spp., Lactococcus spp., Leuconostoc cremoris, Saccharomyces spp., or Streptococcus spp., alone or in combination. Nine studies used a single strain probiotic agent, four combined two probiotic strains, one combined three probiotic strains, one product included ten probiotic agents, and one study included two probiotic arms that used three and two strains respectively. The risk of bias was determined to be high in 8 studies and low in 8 studies. Available case (patients who did not complete the studies were not included in the analysis) results from 15/16 trials reporting on the incidence of diarrhea show a large, precise benefit from probiotics compared to active, placebo or no treatment control. The incidence of AAD in the probiotic group was 9% compared to 18% in the control group (2874 participants; RR 0.52; 95% CI 0.38 to 0.72; I(2) = 56%). This benefit was not statistically significant in an extreme plausible (60% of children loss to follow-up in probiotic group and 20% loss to follow-up in the control group had diarrhea) intention to treat (ITT) sensitivity analysis. The incidence of AAD in the probiotic group was 16% compared to 18% in the control group (3392 participants; RR 0.81; 95% CI 0.63 to 1.04; I(2) = 59%). An a priori available case subgroup analysis exploring heterogeneity indicated that high dose (≥5 billion CFUs/day) is more effective than low probiotic dose (< 5 billion CFUs/day), interaction P value = 0.010. For the high dose studies the incidence of AAD in the probiotic group was 8% compared to 22% in the control group (1474 participants; RR 0.40; 95% CI 0.29 to 0.55). For the low dose studies the incidence of AAD in the probiotic group was 8% compared to 11% in the control group (1382 participants; RR 0.80; 95% CI 0.53 to 1.21). An extreme plausible ITT subgroup analysis was marginally significant for high dose probiotics. For the high dose studies the incidence of AAD in the probiotic group was 17% compared to 22% in the control group (1776 participants; RR 0.72; 95% CI 0.53 to 0.99; I(2) = 58%). None of the 11 trials (n = 1583) that reported on adverse events documented any serious adverse events. Meta-analysis excluded all but an extremely small non-significant difference in adverse events between treatment and control (RD 0.00; 95% CI -0.01 to 0.02).

AUTHORS' CONCLUSIONS

Despite heterogeneity in probiotic strain, dose, and duration, as well as in study quality, the overall evidence suggests a protective effect of probiotics in preventing AAD. Using 11 criteria to evaluate the credibility of the subgroup analysis on probiotic dose, the results indicate that the subgroup effect based on dose (≥5 billion CFU/day) was credible. Based on high-dose probiotics, the number needed to treat (NNT) to prevent one case of diarrhea is seven (NNT 7; 95% CI 6 to 10). However, a GRADE analysis indicated that the overall quality of the evidence for the primary endpoint (incidence of diarrhea) was low due to issues with risk of bias (due to high loss to follow-up) and imprecision (sparse data, 225 events). The benefit for high dose probiotics (Lactobacillus rhamnosus or Saccharomyces boulardii) needs to be confirmed by a large well-designed randomized trial. More refined trials are also needed that test strain specific probiotics and evaluate the efficacy (e.g. incidence and duration of diarrhea) and safety of probiotics with limited losses to follow-up. It is premature to draw conclusions about the efficacy and safety of other probiotic agents for pediatric AAD. Future trials would benefit from a standard and valid outcomes to measure AAD.

How does comorbidity affect cost of health care in patients with irritable bowel syndrome? A cohort study in general practice

Background

Irritable bowel syndrome (IBS) is associated with other disorders (comorbidity), reduced quality of life and increased use of health resources. We aimed to explore the impact of comorbidity on cost of health care in patients with IBS in general practice.

Methods

In this cohort study 208 consecutive patients with IBS (Rome II) were recruited. Sociodemographic data, IBS symptoms, and comorbidity (somatic symptoms, organic diseases and psychiatric disorders) were assessed at baseline. Based on a follow up interview after 6-9 months and use of medical records, IBS and non-IBS related health resource use were measured as consultations, hospitalisations, use of medications and alternative health care products and sick leave days. Costs were calculated by national tariffs and reported in Norwegian Kroner (NOK, 1 EURO equals 8 NOK). Multivariate analyses were performed to identify predictors of costs.

Results

A total of 164 patients (mean age 52 years, 69% female, median duration of IBS 17 years) were available at follow up, 143 patients (88%) had consulted their GP of whom 31 (19%) had consulted for IBS. Mean number of sick- leave days for IBS and comorbidity were 1.7 and 16.3 respectively (p < 0.01), costs related to IBS and comorbidity were 954 NOK and 14854 NOK respectively (p < 0.001). Age, organic diseases and somatic symptoms, but not IBS severity, were significant predictors for total costs.

Conclusion

Costs for health resource use among patients with IBS in general practice were largely explained by comorbidity, which generated ten times the costs for IBS.

Perceived food intolerance in subjects with irritable bowel syndrome-- etiology, prevalence and consequences

OBJECTIVES

This study estimates the prevalence of perceived food intolerance and its consequences in subjects with irritable bowel syndrome (IBS), evaluates the utility of common tests for food intolerance, studies the relation between perceived food intolerance and other disorders, and discusses the etiology.

DESIGN

Cross-sectional study.

SETTING

National health survey.

SUBJECTS

A selection of the population (n=11,078) in Oppland county, Norway, was invited to a health screening, and a sample of subjects with IBS were included in the study.

INTERVENTIONS

A medical history of food intolerance, musculoskeletal pain, mood disorders and abdominal complaints was taken, and tests were performed for food allergy and malabsorption. A dietician evaluated the dietary habits of the subjects.

RESULTS

Out of 4,622 subjects with adequately filled-in questionnaires, 84 were included in the study, 59 (70%) had symptoms related to intake of food, 62% limited or excluded food items from the diet and 12% had an inadequate diet. The mean numbers of food items related to symptoms and the number of foods limited or excluded from the diet were 4.8 and 2.5, respectively. There were no associations between the tests for food allergy and malabsorption and perceived food intolerance. Perceived food intolerance was unrelated to musculoskeletal pain and mood disorders.

CONCLUSIONS

Perceived food intolerance is a common problem with significant nutritional consequences in a population with IBS. The uselessness of current antibody tests and tests for malabsorption and the lack of correlation to psychiatric co-morbidity make the etiology obscure.

How useful are the Rome II criteria for identification of upper gastrointestinal disorders in general practice?

OBJECTIVE

The Rome II criteria are a classification of functional gastrointestinal disorders. It is not known whether they can be used as a diagnostic tool. This study evaluates the agreement between GPs and the Rome II criteria on the diagnosis of upper gastrointestinal disorders.

MATERIAL AND METHODS

Consecutive patients with abdominal complaints were included in this pragmatic cross-sectional study. All patients answered a questionnaire based on the Rome II criteria. The diagnoses based on these criteria were compared with the GPs' diagnoses.

RESULTS

A total of 549 consecutively selected patients were included in the study. The agreement between GPs and the Rome II criteria was 65%, kappa 0.34 (CI 0.27-0.41). The agreement was lower when dyspepsia and gastroesophageal reflux/functional heartburn were evaluated separately. The positive and negative predictive values of the Rome II criteria varied between 29-58% and 82-90%, respectively, in various groups of patients with confirmed diagnoses.

CONCLUSIONS

The GPs' diagnoses differed from those based entirely on the Rome II criteria. Strict adherence to the criteria will result in other diseases being disregarded. The diagnoses of upper gastrointestinal disorders should be based on all available information and the Rome II criteria used only as an additional aid to improve the precise classification of functional disorders.

The value of a general therapeutic approach in subjects with irritable bowel syndrome

BACKGROUND

The general therapeutic approach is the cornerstone in the management of irritable bowel syndrome, but the effect is poorly documented.

AIM

To evaluate the effect of the general therapeutic approach for irritable bowel syndrome.

METHODS

Subjects with irritable bowel syndrome identified in a public screening were included. Scores for abdominal symptom (range 0-12), musculoskeletal pain and mood disorders were calculated. After exclusion of other disorders, a doctor presented irritable bowel syndrome as a positive diagnosis, gave information, reassurance and lifestyle advice, but no pharmacotherapy. A dietician gave dietary advice. There was a follow-up after 6 months.

RESULTS

Sixty-five persons (females/males: 44/21) with mean age 49 years (range 31-76) were included, 31 (48%) were recommended dietary changes. Twenty subjects (31%) had satisfactory relief of symptoms after 6 months. The scores for abdominal symptom was reduced from 3.1 to 2.2 (P = 0.007), the reduction was 2.2 in the diarrhoea-predominant group given advice compared with 0.4 in the other subjects (P = 0.035). Previous consultations for the complaints, visits for psychiatric disorders, and presence of mood disorders were predictors of persistent complaints.

CONCLUSIONS

There was a significant relief of symptoms after 6 months, those with psychological co-morbidity responded less well. The effect of dietary advice was only seen in those with diarrhoea-predominant irritable bowel syndrome.

Comorbidity of irritable bowel syndrome in general practice: a striking feature with clinical implications

BACKGROUND

Somatic comorbid symptoms might identify irritable bowel syndrome patients with different aetiologies and needs of treatment.

AIMS

To measure comorbid symptoms in patients with irritable bowel syndrome in general practice, and to explore characteristics of patients with low, intermediate and high somatic comorbidity.

METHODS

Prospective study of 208 of 278 consecutive patients with irritable bowel syndrome (Rome II) in nine general practices. Questionnaires assessed 22 comorbid symptoms (subjective health complaint inventory), psychosocial factors including psychological distress (Symptom Check list-10) and quality of life (Short form-12). Subjective health complaint data from 1240 adults (controls) constituted a reference material. Patients with low, intermediate and high somatic comorbidity were identified by a somatic comorbidity score (17 subjective health complaint items). Health care seeking was assessed after 6-9 months.

RESULTS

Patients with irritable bowel syndrome (67% females, mean age 50, s.d. 16) reported 20 of 22 comorbid symptoms significantly more frequent than controls (odds ratios = 2-7, P < 0.001). The somatic comorbidity score correlated with psychological distress (R = 0.46, P < 0.001). Patients with high somatic comorbidity reported higher levels of mood disorder, health anxiety, neuroticism, adverse life events and reduced quality of life and increased health care seeking when compared to those with low and intermediate somatic comorbidity (P-values < 0.05).

CONCLUSIONS

Our findings support the hypothesis that structured assessment of comorbid somatic symptoms might identify subgroups with different aetiology and needs of treatment.

Lactose malabsorption in a population with irritable bowel syndrome: prevalence and symptoms. A case-control study

BACKGROUND

Symptoms after intake of milk are common in persons with irritable bowel syndrome (IBS). The aims of this study were to compare the prevalence of lactose malabsorption (LM) and symptoms related to intake of milk and lactose in subjects with IBS with that of healthy volunteers, and to search for symptoms that are characteristic of LM.

METHODS

A case-control study in a Norwegian population was initiated. Subjects with IBS were asked for symptoms related to intake of milk and lactose, tested for LM, and compared with a group of healthy volunteers.

RESULTS

The study comprised a total of 187 persons (82 with IBS and 105 volunteers), females/males: 138/49, mean age 47 years. In subjects with IBS and in healthy volunteers, LM was present in 3/74 (4.1%) and 4/105 (3.8%), respectively (ns), milk-related symptoms in 32/79 (40%) and 13/105 (12%), respectively (P < 0.001) and symptoms after intake of lactose in 28/74 (38%) and 21/104 (20%), respectively (P=0.01). Borborygmi starting within 5 h after intake of lactose and lasting for more than 2 h indicated LM (OR 61 (95% CI: 8-475), P < 0.001).

CONCLUSIONS

IBS and LM are unrelated disorders in a Norwegian population. Milk-related symptoms and symptoms after intake of lactose are unreliable predictors for LM. Precise symptom-based criteria might enhance the diagnostic accuracy for LM.

Diagnosing irritable bowel syndrome: poor agreement between general practitioners and the Rome II criteria

BACKGROUND

The new guidelines for diagnosing irritable bowel syndrome (IBS) in clinical practice recommend the use of the Rome II criteria. In this study the agreement between general practitioners (GPs) and the Rome II criteria for diagnosing of IBS and functional bowel disorders (FBD) is examined.

METHODS

Consecutive patients in general practice were asked to report on abdominal complaints, for which they had consulted or wanted to consult a GP. Patients with such complaints completed a questionnaire based on the Rome II criteria for FBD. After consultations, the GPs reported their diagnoses on the abdominal complaints.

RESULTS

Of 3097 screened patients, 553 patients were diagnosed by their GP and had complete data in the questionnaire. Of these patients, 107 had IBS according to the GPs and 209 had IBS according to the Rome II criteria (agreement 58%, kappa 0.01 (CI: -0.06; 0.09)). Agreement on IBS and FBD in patients without organic disease, without reflux or dyspepsia and in patients with a verified diagnosis was 45%-58%, with kappa values from -0.02 to 0.13. IBS and FBD cases were diagnosed by the Rome II criteria more often than by the GPs in all these groups of patients (P < 0.001). In patients with diagnostic discrepancies concerning IBS, 'stress-related symptoms' was predictive of a diagnosis of IBS made by the GPs only (OR 2.17 (CI: 1.1; 4.2)).

CONCLUSIONS

This study shows poor agreement in the diagnosis of IBS between GPs and the Rome II criteria. Therefore, current knowledge about IBS based on strict criteria is not necessarily transferable to patients with IBS in general practice.

[The chain that saves life. Prehospital treatment of myocardial infarction]

A 53-year old woman living in a rural area 220 km from the nearest hospital experienced an acute myocardial infarction. The local doctor contacted the emergency service and requisitioned an air ambulance. 29 minutes later the physician-manned helicopter arrived, and thrombolytic treatment was started after 15 minutes. The patient arrived at the county hospital 35 minutes later, after having been electroconverted three times because of ventricular fibrillation. The patient was discharged from hospital ten days later with no cerebral sequelae, and left ventricular ejection fraction 49%. This example shows that active use of emergency communications systems and air ambulances enables both prompt thrombolytic treatment and the effective treatment of complications associated with myocardial infarction to be accomplished.