Meta-analysis of two-arm studies: Modeling the intervention effect from survival probabilities.

Pooling the hazard ratios is not always feasible in meta-analyses of two-arm survival studies, because the measure of the intervention effect is not systematically reported. An alternative approach proposed by Moodie et al. is to use the survival probabilities of the included studies, all collected at a single point in time: the intervention effect is then summarised as the pooled ratio of the logarithm of survival probabilities (which is an estimator of the hazard ratios when hazards are proportional). In this article, we propose a generalization of this method. By using survival probabilities at several points in time, this generalization allows a flexible modeling of the intervention over time. The method is applicable to partially proportional hazards models, with the advantage of not requiring the specification of the baseline survival. As in Moodie et al.'s method, the study-level factors modifying the survival functions can be ignored as long as they do not modify the intervention effect. The procedures of estimation are presented for fixed and random effects models. Two illustrative examples are presented.

Testing the WHO Hand Hygiene Self-Assessment Framework for usability and reliability.

BACKGROUND: The World Health Organization (WHO) Hand Hygiene Self-Assessment Framework (HHSAF) was conceived as a structured self-assessment tool to provide a situation analysis of hand hygiene resources, promotion and practices within healthcare facilities. AIM: To perform usability pretesting and reliability testing of the HHSAF. METHODS: The HHSAF draft was developed in consultation with experts to reflect key elements of the WHO Multimodal Hand Hygiene Improvement Strategy. Forty-two facilities were invited to pretest the draft HHSAF and complete a feedback survey. For reliability testing, two users in each facility completed the HHSAF independently. The reliability of each indicator, component subtotal and the overall score were estimated using the variance components model. After each phase, the tool was re-examined and modified as appropriate. FINDINGS: Twenty-seven indicators were selected during drafting. Twenty-six facilities in 19 countries completed pretesting (62% response rate), with total scores ranging from 35 to 480 (mean 262). The HHSAF took less than 2 h to complete for 21 facilities. Most agreed that the HHSAF was 'easy to use' (23/26) and 'useful for establishing facility status with regard to hand hygiene promotion' (24/26). Complete reliability responses were received from 41 facilities in 16 countries. Reliability for the total score for the HHSAF and the subtotal of each of the five components ranged from 0.54 to 0.86. Seven indicators had poor reliability; these were examined for potential flaws and modified accordingly. CONCLUSION: This process confirmed the usability and reliability of this tool for the promotion of hand hygiene in health care.

Use of brain natriuretic peptide to detect previously unknown left ventricular dysfunction in patients with acute exacerbation of chronic obstructive pulmonary disease.

BACKGROUND: Up to 30% of patients with chronic obstructive pulmonary disease (COPD) simultaneously suffer from often-unrecognised chronic heart failure (HF). Their timely identification is challenging as both conditions share similar clinical presentations. OBJECTIVE: To assess the performance of BNP in detecting left ventricular systolic dysfunction in patients with no history of HF admitted for acute exacerbation of COPD in a regional second-care hospital. METHODS: Retrospective medical records analysis of all patients hospitalised between January 2003 and May 2009 with the final diagnosis of acute exacerbation of COPD, and who had undergone BNP dosage at admission followed by an echocardiography. RESULTS: Among the 57 patients included, 13 had left ventricular systolic dysfunction. There was a statistically significant difference of mean BNP values between patients with or without systolic dysfunction (mean 689 pg/ml vs. 340 pg/ml, p = 0.007). For the detection of systolic dysfunction, a BNP level inferior to 100 pg/ml yielded a sensitivity of 92% and a negative predictive value of 91%, whereas BNP higher than 500 yielded a sensitivity of 80% and a positive predictive value of 47%. In a multivariate logistic regression analysis, a BNP value ≥500 (odds ratio 8.5, 95% confidence interval 1.9 to 38.2, p = 0.005) and history of coronary heart disease (odds ratio 5.9, 95% confidence interval 1.01 to 34.7, p = 0.048) remained as independent and mutually adjusted predictors of left ventricular systolic dysfunction. CONCLUSIONS: Our study confirms that BNP can help physicians in identifying heart failure in patients suffering from an acute exacerbation of COPD.

Patient-reported conformity of informed consent procedures and participation in clinical research.

BACKGROUND: There is growing evidence that the quality of informed consent in clinical research is often sub-optimal. AIMS: To explore the conformity of patient recruitment with recommended informed consent procedures among patients who were invited to participate in a clinical study at a general teaching hospital, and to examine the association between consent procedures and the patients' decision to participate. DESIGN AND METHODS: All inpatients discharged during a 1-month period were invited to complete a mailed survey in which they reported whether they were invited to participate in a study and whether 13 recommended elements of informed consent actually occurred. RESULTS: Among 1303 respondents, 265 (20.3%) reported that they had been invited to participate in a study, and 191 (72.1%) accepted. While the majority of potential participants were fully informed about practical issues related to the study (e.g. what their participation would consist in), <50% were informed of possible risks or benefits, and only 20% about the origin of the study funds. Only 60% reported satisfactory answers to items assessing the overall information process (e.g. explanations were easy to understand). Older and sicker patients reported lower levels of conformity with informed consent procedures, as did patients who refused to participate in a study. CONCLUSION: Our results confirm that informed consent procedures fail to meet standards for many patients. In particular, consent information should be adapted to the needs of older and sicker patients. Improving the quality of informed consent may increase patients' participation in clinical research.

Meta-analysis of binary outcomes from two-by-two tables when the length of follow-up varies and hazards are proportional.

Odds ratios (ORs) and relative risks (RRs) are sensitive to the length of follow-up. In meta-analyses, pooling such results from studies with different lengths of follow-up may lead to an artificial heterogeneity and discrepancy caused by the choice of the summary index. In this article, we explore the utility of a meta-analysis method that uses the ratio of logarithms of survival probability as the measure of association, and that avoids the problems mentioned above when hazards are proportional. Meta-analyses of ORs, RRs and ratios of logarithms of survival probability are compared through a simulation study, in which data are simulated from a proportional hazard model and the length of follow-up varies across studies using realistic patterns of variability. Results show that the heterogeneity increases with the variability of length of follow-up for OR and RR, but not for the ratio of the logarithms of survival probability. A published meta-analysis is used to illustrate the method.

The association between body mass index and patients' experiences with inpatient care.

OBJECTIVE: To explore the association between patients' body mass index (BMI) and their experiences with inpatient care. DESIGN: Cross-sectional. Mail survey. SETTING: University Hospital of Geneva. PARTICIPANTS: Questionnaires were mailed to 2385 eligible adult patients, 6 weeks after discharge (response rate = 69%). MAIN OUTCOME MEASURES: Patients' experiences with care were measured using the Picker inpatient survey questionnaire. BMI was calculated using self-reported height and weight. Main dependent variables were the global Picker patient experience (PPE-15) score and nine dimension-specific problem scores, scored from 0 (no reported problems) to 1 (all items coded as problems). We used linear regressions, adjusting for age, gender, education, subjective health, smoking and hospitalization, to assess the association between patients' BMI and their experiences with inpatient care. RESULTS: Of the patients, 4.8% were underweight, 50.8% had normal weight, 30.3% were overweight and 14.1% were obese. Adjusted analysis shows that compared with normal weight, obesity was significantly associated with fewer problematic items in the surgery-related information domain, and being underweight or overweight was associated with more problematic items in the involvement of family/friends domain. The global PPE-15 score was significantly higher (more problems) for underweight patients. CONCLUSIONS: Underweight patients, but not obese patients, reported more problems during hospitalization.

Speed trends of major cycling races: does slower mean cleaner?

Since doping improves athletic performance, anti-doping policies should have the opposite effect. This analysis examined whether changes in the speed of major cycling races reflect recent anti-doping efforts. Average speeds of 5 (th) place finishers of the Tour de France, Giro d'Italia, and Vuelta a España cycling races were obtained for the period 1990-2009. Between 1990 and 2004, the average speed had been increasing by 0.16 km/h per year (p<0.001). In a downturn, since 2004, the average speed has decreased by 0.22 km/h per year (p=0.031). The slowing down of professional cycling races is compatible with the hypothesis that recent anti-doping efforts in professional cycling have curbed the use of performance-enhancing substances.

Assessment of patients' tendency to give a positive or negative rating to healthcare.

BACKGROUND: Adjustment of patient satisfaction scores for case-mix variables such as age and sex may lead to overadjustment. The patient's tendency to rate healthcare positively or negatively may be the only variable that should be adjusted to improve the comparability of satisfaction scores between healthcare providers. OBJECTIVE: To develop a measure of "rating tendency", assess its stability over time, explore its distribution across subgroups of patients and its association with patient opinion scores. DESIGN AND SUBJECTS: A scale based on 10 hypothetical scenarios describing hospital care episodes was developed. It was administered both before and after hospitalisation to 203 patients programmed for elective orthopaedic surgery in a Swiss teaching hospital. A problem score regarding the actual hospitalisation was obtained at follow-up. RESULTS: The rating tendency scale had good internal consistency (Cronbach alpha 0.85), and factor analysis confirmed that it measured a single underlying concept. However, the correlation between prehospitalisation and posthospitalisation measures was moderate (intraclass correlation coefficient 0.55, p<0.001), as was the correlation with the hospitalisation problem score (Spearman r = -0.22, p = 0.002). The pattern of rating tendency across subgroups of respondents mirrored the pattern of problem scores. Adjusting for the rating tendency had little effect on comparisons of problem scores between subgroups of patients, all of whom were treated at the same hospital. CONCLUSIONS: A patient's "rating tendency" can be measured using a reliable 10-item scale. The utility of adjusting satisfaction scores for rating tendency when comparing hospitals remains to be tested.

Measuring quality of patient information documents with an expanded EQIP scale.

OBJECTIVE: To develop an expanded version of the ensuring quality information for patients (EQIP) scale to measure quality of patient information documents. METHODS: We added 16 new items to the 20-item EQIP scale. The 36 items addressed document content, structure, and identification data. The new tool was used to rate the quality of 73 leaflets describing medical care procedures, used at a university hospital. Assessment rules were clarified on 25 documents; the remaining 48 leaflets were independently rated by two assessors. RESULTS: Inter-rater reliability was very good (mean item-specific kappa statistic on 48 documents=0.84). The intraclass correlation coefficient for the global score was 0.95. The mean global conformity score on all items was 44 (range: 21-76, S.D.=10). Most documents stated the purpose of the medical intervention (74% fully adequate), described qualitative risks (64%), used a respectful tone (80%), provided clear information (64%) in a logical order (73%). Fewer quantified risks (7%), were balanced (33%), used everyday language (22%), provided contact details (28%), identified authors (25%) and funding sources (4%). None gave evidence-based references nor clearly mentioned patient participation. CONCLUSIONS: The expanded EQIP scale was reliable, and proved useful for analysis of patient information documents. Documents partially met international standards for quality patient information. PRACTICE IMPLICATIONS: Document producers' efforts should focus on respecting guidelines and including patients.

Patient assessments of a hypothetical medical error: effects of health outcome, disclosure, and staff responsiveness.

OBJECTIVE: To assess whether patients' perceptions of a hypothetical medical error are influenced by staff responsiveness, disclosure of error, and health consequences of the error. DESIGN: Hypothetical scenario describing a medication error submitted by mail. Three factors were manipulated at random: rapid v slow staff responsiveness to error; disclosure v non-disclosure of the error; and occurrence of serious v minor health consequences. PARTICIPANTS: Patients discharged from hospital. MEASURES: Assessment of care described in the scenario as bad or very bad, rating of care as unsafe, and intent to not recommend the hospital. RESULTS: Of 1274 participants who evaluated the scenario, 71.4% rated health care as bad or very bad, 60.2% rated healthcare conditions as unsafe, and 25.5% stated that they would not recommend the hospital. Rating health care as bad or very bad was associated with slow reaction to error (odds ratio (OR) 2.8, 95% CI 2.1 to 3.6), non-disclosure of error (OR 2.0, 95% CI 1.5 to 2.6), and serious health consequences (OR 3.4, 95% CI 2.6 to 4.5). Similar associations were observed for rating healthcare conditions as unsafe and the intent to not recommend the hospital. Younger patients were more sensitive to non-disclosure than older patients. CONCLUSIONS: Former patients view medical errors less favorably when hospital staff react slowly, when the error is not disclosed to the patient, and when the patient suffers serious health consequences.

Variability in women's desire for information about mammography screening: implications for informed consent.

This study aimed to explore women's desire for information about mammography screening in a population where overly optimistic perceptions of mammography screening were common. A self-administered questionnaire was completed by 2305 women aged 50-69 years, residents of Geneva, Switzerland. The questionnaire assessed the respondents' wish to receive information (detailed, general or none) about seven aspects of mammography screening: personal risk of breast cancer, prevention of breast cancer, benefits of mammography screening, limitations, minor inconveniences, more important problems, why some people oppose screening. The seven items formed a unidimensional scale (Cronbach's alpha=0.91). Women differed considerably in their stated desire for detailed or general information. For instance, whereas 14% wanted detailed information on all items and 36% general information on all items, 39% were not interested in detailed information on the limits and adverse consequences of screening. In multivariate analysis, some women's characteristics were associated with higher scores of desire for information, but little variance was explained (adjusted R=0.05). In conclusion, many women currently decline information about mammography screening that is deemed relevant by public health authorities. This may lead to poorly informed choices in an important area of prevention.

[Length of hospital stay, discharge planning, and policy regarding the shortening of hospital stays: patients'and hospital care providers'point of view]. / Durée d'hospitalisation, programmation de la sortie et politique de raccourcissement des séjours: avis des patients et des soignants.

BACKGROUND: In the context of health care cost containment, we interviewed hospitalized patients and their health care teams concerning the length of stay they considered necessary and hospital discharge. Patients were also interviewed on the present tendency to shorten hospital stays. METHODS: Prospective study conducted in a subacute internal medicine ward with 254 consecutive patients and their health care teams. RESULTS: The mean evaluation of the length of stay considered as necessary was not significantly different between patients (9.7 days, SD=9.5) and their health care teams (9.6, SD=8.5). However, agreement between the two parties was moderate (r=0.64). Hospital discharge was considered as planned in similar proportions (18% vs 22% respectively), but was reported as more 'assured' by health care teams than by patients (p<0.001). Health care teams and patients approved discharge planning in 200 cases (63.3%), but agreement was only moderate (Kappa 0.43, IC 95%=0.34-0.51). Regarding the tendency to shorten hospital stays, patients'responses were favorable in only 9%, clearly unfavorable in 17% and disclosed explicit fears in 54% of the cases. CONCLUSIONS: These results show that what patients and health care teams consider the necessary length of stay and the right time for hospital discharge can diverge notably. They highlight the difficulties of medical decisions in the context of cost containment, and the fundamentally asymmetrical character of the relationship between patients and health care teams.

Acceptability of identification bracelets for hospital inpatients.

OBJECTIVE: To evaluate whether hospitalised patients would agree to wear an identification bracelet and whether patient acceptability is improved by more detailed explanations or by using a code instead of a name on the bracelet. DESIGN: Patient survey that tested two variables in a randomised factorial design. Explanations about identification bracelets were given (a) with or without examples of situations where patient identification may be important, and (b) with the patient name or an anonymous code appearing on the bracelet. SETTING: Swiss teaching hospital where wearing of identification bracelets was not systematic. PARTICIPANTS: Adult patients discharged from hospital (n = 1411). MAIN OUTCOME MEASURES: Patients' responses to the questions: (a) should the hospital introduce a compulsory identification bracelet? and (b) would the patient agree to wear such a bracelet? RESULTS: Globally, 83.9% of patients thought that the hospital should introduce bracelets and 90.2% stated that they would agree to wear one. Providing examples increased support for both the hospital policy (87.9% v 79.2%, p<0.001) and personal acceptance (92.2% v 88.1%, p = 0.015). Whether or not the bracelet carried the patient's name or an anonymous code did not influence patient choice. CONCLUSIONS: The majority of patients were in favour of wearing an identification bracelet during their hospital stay. This proportion increased significantly when an explanation based on examples of the consequences of incorrect patient identification had been provided.

Relationship between hospital length of stay and quality of care in patients with congestive heart failure.

OBJECTIVE: To determine the relationship between hospital length of stay (LOS) and quality of care in patients admitted for congestive heart failure (CHF). METHODS: This observational study was conducted in the medical wards of the Geneva University Hospitals, Geneva, Switzerland. A random sample of 371 patients was drawn from the 1084 patients discharged alive with a principal diagnosis of CHF between January 1997 and December 1998. Explicit criteria grouped into three scores were used to assess the quality of processes of care: admission work-up (admission score); evaluation and treatment during the stay (treatment score); and readiness for discharge (discharge score). The association between LOS and quality of care was analysed using linear regression with adjustment for clinical characteristics. RESULTS: The mean proportion of criteria met were 80% for the admission score, 66% for the treatment score, and 76% for the discharge score. Mean (SD) LOS was 13.2 (8.8) days. The admission score was not associated with LOS, but the treatment score increased by 0.5% (95% CI 0.3 to 0.7; p < 0.001) with each additional day in hospital and the discharge score increased by 2.5% (95% CI 1.6 to 3.3; p < 0.001) per day from admission to day 10 but remained unchanged thereafter. Adjustment for potential confounders did not substantially modify these relationships. CONCLUSIONS: In patients with CHF there is a significant association between LOS and the quality of the treatment provided, as well as with readiness for discharge. Appropriate reorganisation of processes of care should accompany attempts at reducing LOS to avoid detrimental effects on quality of care.

Diagnostic tests for rheumatoid arthritis: comparison of anti-cyclic citrullinated peptide antibodies, anti-keratin antibodies and IgM rheumatoid factors.

OBJECTIVES: To examine the value of anti-cyclic citrullinated peptide (anti-CCP) antibodies, anti-keratin antibodies (AKA) and immunoglobulin M rheumatoid factors (IgM RF) in discriminating between rheumatoid arthritis (RA) and other rheumatic diseases, and to determine whether the clinical manifestations or severity of erosions in RA are associated with anti-CCP positivity. METHODS: In a cross-sectional study, we determined the concentrations or titres of these three markers in 179 RA patients and 50 controls. Erosions were quantified using the Larsen score in 129 patients. RESULTS: Sensitivity was highest for IgM RF (75%), followed by anti-CCP antibodies (68%) and AKA (46%). Specificity was highest for anti-CCP antibodies (96%), followed by AKA (94%) and IgM RF (74%). A correlation with clinical manifestations and severity of erosions was observed mainly for IgM RF positivity. CONCLUSIONS: With their excellent specificity, anti-CCP antibodies can be useful in establishing the diagnosis of RA, but IgM RF is a better predictor of disease severity.

Comparative study of different enzyme immunoassays for measurement of IgM and IgA rheumatoid factors.

OBJECTIVE: To compare the value of various IgM and IgA rheumatoid factor (RF) tests for the diagnosis of rheumatoid arthritis (RA). METHODS: Firstly, the latex test, one global assay (for IgM, IgA, and IgG RF), six IgM, and four IgA RF assays were compared in a particularly challenging situation-that is, with 67 patients with RA, many of whom were latex negative, and 91 non-RA controls, many of whom were latex positive. More detailed evaluation followed with three IgM RF tests (two commercially available kits and one assay developed in our laboratory) and two IgA RF tests (one commercially available and one from our laboratory) in two more representative samples of rheumatological patients (146 RA and 75 non-RA controls). RESULTS: Diagnostic performance differed considerably between the assays. For IgM RF detection the highest sensitivity (88%) was obtained with the Diamedix kit (specificity 67%) and for IgA RF with the Inova kit (sensitivity 65%, specificity 88%). Combining one IgM and one IgA RF test improved diagnostic performance when both tests were in agreement, but at the cost of yielding 15-27% of discrepant results which did not help in ruling RA in or out. Mean concentration values differed significantly among IgM RF tests, and in most cases concentrations were not correlated. CONCLUSIONS: Available tests for IgM RF isotype vary in accuracy, and none is uniformly better than all the others. For IgA RF isotype, the Inova kit appears to be the best. Quantitative results cannot be compared across tests. Combination of one IgM and one IgA RF test may improve diagnostic accuracy.

Effectiveness of a computer-tailored smoking cessation program: a randomized trial.

BACKGROUND: From a public health perspective, prevention of cancer and cardiovascular diseases requires effective smoking cessation programs that can be used on a large scale. OBJECTIVE: To test the effectiveness of a new computer-tailored smoking cessation program vs no intervention. METHODS: Randomized controlled trial, in the French-speaking part of Switzerland, September 20, 1998, to December 31, 1999. Potential participants were randomly selected from a general population register and recruited by mail. Daily cigarette smokers who wished to participate (N = 2934) were randomized to either the program or no intervention. A mean of 1.5 times per 6 months, participants in the active arm received by mail a computer-tailored counseling letter based on their answers to a questionnaire and stage-matched booklets. The counseling letters were tailored to the participants' stage of change (categorized as precontemplation [no intention of quitting smoking in the next 6 months], contemplation [seriously considers quitting in the next 6 months], or preparation [has decided to quit in the next 30 days]), level of tobacco dependence, self-efficacy, and personal characteristics. The outcome measure was self-reported abstinence (no puff of tobacco smoke in the past 4 weeks) 7 months after entry into the program. RESULTS: Abstinence was 2.6 times greater in the intervention group than in the control group (5.8% vs 2.2%, P<.001). The program was effective in "precontemplators" who were not motivated to quit smoking at baseline (intervention vs control, 3.8% vs 0.8%; P =.001) and was effective regardless of perceived difficulty in quitting smoking at baseline. CONCLUSIONS: The program was effective in increasing smoking cessation rates. Because it can reach a large number of smokers, this program can substantially contribute to disease prevention at a population level.

Misconceptions about efficacy of mammography screening: a public health dilemma.

OBJECTIVE: This study assessed accuracy of women's opinions about reduction in mortality from breast cancer attributable to mammography screening. DESIGN: Cross sectional survey. SETTING: General population of Geneva, Switzerland. PARTICIPANTS: 895 randomly selected women aged 40 to 80 years, free of breast cancer. RESULTS: Women estimated the proportion of deaths from breast cancer that regular mammography screening prevents in women over age 50. Only 19.3% of the respondents assessed screening efficacy realistically (that is, reduction by about one fourth); 52.0% overestimated efficacy; 26.0% "didn't know", and 2.6% stated that screening prevents no death. Women who believed mammography screening to be effective had more positive attitudes toward screening (higher scores of pros and lower scores of cons) and were more likely to plan to have a mammogram (both p<0.001). Lack of opinion about the benefit of mammography screening was more common among women who had not consulted a gynaecologist recently (p=0.02) nor had had a mammogram during the past two years (p=0.009), who had no opinion about their risk of breast cancer (p<0.001), and who were 70 to 80 years old (p=0.04). Compared with women who provided realistic estimates of screening efficacy, those who overestimated efficacy believed to be at higher risk of breast cancer than other women (p=0.04) and were more likely to be Swiss nationals (p=0.001). CONCLUSIONS: Most women overestimated and many were uninformed about the efficacy of mammography screening. Therefore, few women were able to take truly informed decisions about screening mammography.