Methodologic problems in clinical trials in heart failure

HEALTH STATUS ASSESSMENT METHODS FOR ADULTS: Past Accomplishments and Future Challenges

Over the past 30 years, health status assessment methods for adults have proliferated. Numerous generic, disease-specific, and preference-based measures now exist that tap diverse aspects of functioning, well-being, symptom states, and subjective perceptions of health. The evolution of the state of the art in adult health status assessment is reviewed. Applications of these tools in health services research, health policy, and clinical practice are discussed. Recommendations are offered for selecting among the armamentaria of tools. Conceptual and methodological challenges that confront instrument users and developers alike are identified and discussed.

Health-related quality of life. A guide for the health professional

The importance of evaluating health care in terms of patients' quality of life has only recently been acknowledged in the context of outcomes research and the measurement of quality of care. As a health professional, trying to choose the appropriate health status or health-related quality of life (HRQOL) measure can be daunting, as one is faced with a bewildering array of choices. The purpose of this article is to describe the process by which professionals might make a choice about measures in outcomes research. The article includes examples and rationale for using generic or disease-specific HRQOL measures. In addition, examples are provided of HRQOL assessment in two adult chronic disease applications: asthma and congestive heart failure.

Methods of assessing the impact of climacteric complaints on quality of life

Quality of life is an important outcome that reflects the way patients feel and function. Assessing the impact of a condition on quality of life is particularly relevant in symptomatic conditions such as the menopause. A range of measurement tools are available for monitoring how symptoms, typical of the climacteric period, affect patients with regard to their well-being, sleep disturbance, other somatic symptoms, cognitive function and sexual functioning. However, to gain a valid assessment of quality of life and the effects of treatment in the menopause, only standard and well-validated measurement tools should be used. The appropriateness of relying on the use of psychiatric rating scales to assess mood is questionable. Results obtained from an increasing number of controlled clinical studies indicate that treatment with oestrogen, in addition to alleviating vasomotor symptoms, can substantially improve patients' quality of life.

Classification of heart failure in population based research: an assessment of six heart failure scores

Several scores based on symptoms and signs have been developed to assess the presence of heart failure. The goal of this study was to compare six heart failure scores in non-hospitalised subjects and to determine their usefulness in population based research. The scores were applied to 54 participants of a population based study. All underwent a complete medical examination, including chest X-ray, electrocardiography and Doppler echocardiography. Using all information available, a cardiologist, unaware of the results of the scores, clinically classified participants as having no, possible or definite heart failure. Sensitivity, specificity, predictive values and receiver operating characteristics were calculated, using the cardiologist's assessment as a gold standard. The cardiologist judged definite or possible heart failure to be present in 17 persons. All scores had a high sensitivity for the detection of definite heart failure, whereas the study of men born in 1913 and Walma's score had the highest sensitivity for the combination of possible and definite heart failure. Gheorgiade's and the Boston score had the highest positive predictive values. In conclusion, five of the six scores we studied are broadly similar in the detection of heart failure. The men born in 1913 score relies heavily on the assessment of dyspnea, resulting in a relatively large number of false positives. Although the scores are useful in detecting manifest heart failure, objective measurements of cardiac function appear necessary to reduce the false positive rate and accurately detect early stages of heart failure.

Outcomes for older men and women with congestive heart failure

OBJECTIVES

To describe and compare outcomes for men and women discharged alive following a hospitalization for congestive heart failure (CHF).

DESIGN

Prospective cohort study.

PARTICIPANTS

A total of 519 patients, aged > or = 65, who were discharged alive after a hospitalization for CHF (DRG = 127).

MEASUREMENTS

Outcomes (Activities of Daily Living (ADLs), shortness of breath when walking, perceived health, living situation, rehospitalization, and mortality) were measured at 3 times (6 weeks, 6 months, and 1 year) post-discharge.

RESULTS

The 205 men were, on average, younger (77 +/- 7 vs 80 +/- 8, P < .001), wealthier (46% vs 21% earned > or = $10,000, P < .001), and more often married (50% vs 19%, P < .001). Men were more likely than women to have a previous history of CHF (71% vs 63%, P = .052). Men also had higher 1-year mortality than women (48% vs 35%, P = .009), even after adjusting for age, comorbidity, physiological severity (APACHE II APS and RAND discharge instability), radiological evidence of CHF, prior ADLs, walking ability, living situation, and perceived health. Men and women survivors at 1-year had similar and substantial impairment for all non-fatal outcomes considered (all P values > or = .489). Their adjusted mean ADL scores were consistent with complete dependence on one essential activity (range 0-6 dependencies); 35% were short of breath walking less than 1 block; 62% had fair or poor perceived health; 32% received some formal care; and 46% were rehospitalized within 1 year of discharge.

CONCLUSIONS

Men with CHF have a higher mortality than women with CHF. Men and women who survive have similar and substantial impairment for all non-fatal outcomes (ADLs, shortness of breath upon walking, perceived health, living situation, and rehospitalization).

A comparison of quality of life scores in patients with angina pectoris after angioplasty compared with after medical therapy. Outcomes of a randomized clinical trial. Veterans Affairs Study of Angioplasty Compared to Medical Therapy Investigators

BACKGROUND

Evaluations of therapy for the treatment of angina have traditionally consisted of a combination of objective measures, such as exercise tolerance, and subjective markers, such as angina attack rate. Recently, the need to assess "how patients feel"--their quality of life (QOL)--has been regarded with increasing importance. Standard instruments are available to assess QOL and its change after therapeutic intervention. Although QOL instruments have been used to assess the efficacy of percutaneous transluminal coronary angioplasty (PTCA), they have not been used previously to compare the impact of PTCA with that of medical therapy in patients with angina pectoris. We report on the changes in self-assessed QOL among patients randomly assigned to treatment by PTCA or medical therapy and relate these measurements to changes in exercise performance and coronary angiograms.

METHODS AND RESULTS

Patients with stable angina, a positive exercise tolerance test, and at least 70% stenosis (index lesion) in the proximal two thirds of one major coronary artery were randomly assigned to receive PTCA or medical therapy. Six months after randomization, each patient underwent repeat exercise testing and coronary angiography. Before randomization and at the 6-month visit, patients completed a self-administered QOL questionnaire that measured physical functioning and psychological well-being. We compared the changes in QOL with changes between the baseline and 6-month exercise tests, stratified by terciles (decrease in duration, 0- to 2-minute increase, and > 2-minute improvement). We also stratified patients by whether there was more or less than 2 SD change (18.8%) in diameter stenosis of the index lesion (initial minus follow-up angiogram), and we related these to changes in QOL measures. One hundred eighty-two patients with one-vessel disease completed baseline and 6-month questionnaires. At baseline, there were no differences in any QOL measurements between treatment groups. At the 6-month follow-up visit, there was greater improvement in both physical functioning and psychological well-being scores for patients receiving PTCA (+7.36 +/- 15.6, PTCA; +1.98 +/- 14.7, medical therapy; P < .02). Improvement in QOL variables was noted only in patients demonstrating an increase in exercise performance. Also, patients assigned to either treatment whose angiograms demonstrated more than 18.8% improvement in index lesion percent stenosis experienced a significant increase in their QOL scores.

CONCLUSIONS

This was the first study of the relative changes in QOL measures assessed with the use of previously validated and standardized instruments in patients randomly assigned to treatment with PTCA or medical therapy. Patients assigned to PTCA demonstrated a significantly greater improvement in both physical and psychological measures. This improvement was noted in patients whose exercise performance improved and whose angiograms demonstrated an improvement in lesion severity.

A comparison of three quality of life instruments in subjects with angina pectoris: the Sickness Impact Profile, the Nottingham Health Profile, and the Quality of Well Being Scale

Three instruments for the assessment of quality of life, the Quality of Well Being index (QWB), the Nottingham Health Profile (NHP) and the Sickness Impact Profile (SIP) were assessed in 59 patients with angina pectoris. The NHP showed increased statistically significant impairment with higher New York Heart Association (NYHA) class in 4 out of 6 subscales but not in single responses to questions on daily life. In the SIP 9 out of 11 dimensions increased with NYHA grade as did the physical and psychosocial subscores and the total score. There were statistically significant increases in six of the eleven dimensions. In the QWB an increase was observed only for two out of four categories employed in this instrument. The QWB was the most difficult to administer and thought likely to be insensitive to changes in anginal pain. There was a high level of agreement in similar dimensions of NHP and SIP. A psychological distress score was evaluated using the Symptom Rating Test and correlated with all summary dimensions of both instruments. The coefficients of variation were lower in SIP than in NHP categories. In conclusion quality of life instruments like NHP and SIP may be able to identify treatment effects in angina patients and so yield a useful addition to the traditional measures employed for the assessment of their condition.

Methods for assessing quality of life in the cardiac arrhythmia suppression trial (CAST)

The CAST was a randomized, double-blind placebo-controlled multicentre trial of antiarrhythmic medications designed to suppress ventricular arrhythmias in patients after an acute myocardial infarction (MI). A collection of 21 items derived from established scales was used to assess aspects of quality of life in CAST. The questions focused on symptoms, mental health, physical functioning, social functioning, life satisfaction, and life expectancy. Additional aspects included exposure to major stressful life events, and perceived social support and social integration. Work status was also recorded. Using the baseline values of 1465 (98%) out of 1498 patients enrolled in the CAST main study between 15 June 1987 and 19 April 1989, the reliability and validity of the scales used in CAST were computed. High internal consistency reliability (> or = 0.70) was found for Symptoms, Mental Health, and Physical Functioning. The discriminative validity, in particular for Symptoms, Mental Health, Physical and Social Functioning, showed that patients with heart failure and previous MI, as well as those suffering from angina and dyspnea, had a worse quality of life than those patients who were not experiencing these symptoms. It was concluded that the scales selected to form the CAST quality of life questionnaire were both reliable and clinically valid for this patient population and therefore could be used to detect disease progression and treatment effects.

The relationship between exercise tolerance and quality of life in angina pectoris

The relationship between exercise tolerance assessed by a conventional exercise stress test using a standard Bruce protocol and quality of life (QoL) was studied in 50 patients with stable angina pectoris (AP). Before the exercise test, patients completed three self-administered QoL questionnaires, the Psychological General Well-Being Index, an Angina-Specific QoL Questionnaire, and Jenkins' Sleep Dysfunction Scale. Total exercise time (r = -0.40) and time until onset of pain (r = -0.44) were significantly correlated with perceived physical limitations. Somatic symptoms were related to total time (r = -0.38). Apart from a significant correlation between depressed mood and total exercise time (r = 0.36), there was no corresponding correlation with well-being and sleep disturbance. These results suggest that exercise stress tests do not reflect quality of life in patients with AP.

Cardiac failure: symptoms and functional status

The associations between exercise capacity, symptoms and specific aspects of quality of life were examined in subjects participating in a trial of the treatment of heart failure. Patients were assessed on entry and after three months treatment. The principle symptoms were fatigue, breathlessness and chest pain. These limited the extent and speed of physical activities, restricted social, leisure and family life and were associated with emotional distress. There were associations between baseline exercise capacity and measures of quality of life. Change in exercise capacity during three months treatment was correlated with changes in measures of symptoms, limitation of activity and quality of life. The findings confirm the value of change in exercise capacity as a measure of functional status and suggest that it should be supported by a limited number of specific measures of quality of life.

Comparison of perceived health status and conventional functional evaluation in stable patients with coronary artery disease

A cross-sectional study of stable coronary hospital patients was carried out to compare perceived health assessment with conventional clinical measures; 93 consecutive patients were studied, 45 of whom had undergone bypass surgery. Exercise tests and clinical functional classification were obtained together with blind concurrent self-responses to the Nottingham Health Profile (NHP), a measure of distress. Coronary arteriography was available for all patients. Patients with negative exercise tests had lower NHP scores (lower levels of distress) than those with positive or inconclusive tests, especially in the energy, pain and physical mobility NHP dimensions (p less than 0.01). High Spearman correlation coefficients were found between exercise performance and energy (rs = -0.51) and pain (rs = -0.36) scores. This correlation was closer than that found with clinical functional class. In these patients, exercise performance closely correlated with perceived distress. Self-perceived health status measures may improve the evaluation of coronary patients based on clinical assessment alone.

Factors of importance when evaluating quality of life in clinical trials

Quality of life (QoL) has during recent years become recognized as an important outcome in clinical trials. But it is not sufficient just to incorporate QoL measures in a trial. Several factors have important repercussions on the results of clinical trials using QoL as an outcome measure. Unless more attention is directed towards factors that may be important when evaluating QoL, the value of including these measurements in clinical trials will be minimized. Important issues pertain to trial design, duration of follow-up, the role of placebo effects, side effects, and confounding variables.

To what extent do congestive heart failure patients in sinus rhythm benefit from digoxin therapy? A systematic overview and meta-analysis

PURPOSE

To reappraise the effectiveness of digoxin for the treatment of congestive heart failure (CHF) in patients with sinus rhythm in light of data from recently published randomized controlled trials and to quantitatively assess its usefulness.

STUDY IDENTIFICATION

Computerized searches of the MEDLINE database were performed, and the reference list of each retrieved article was reviewed.

STUDY SELECTION

Review of more than 360 citations and the reference lists of 19 review articles and 61 potentially relevant articles revealed seven double-blind randomized controlled trials that were included in this overview.

DATA EXTRACTION

Study quality was assessed and descriptive information concerning the study populations, the specific interventions, and clinically relevant outcome measurements was extracted.

RESULTS OF DATA SYNTHESIS

The common odds ratio for CHF deterioration while receiving digoxin versus placebo was 0.28, with a 95% confidence interval of 0.16 to 0.49. Predictors of digoxin benefit included presence of a third heart sound and the severity and duration of CHF.

CONCLUSION

Data from seven trials of high methodologic quality suggest that, on average, one out of nine patients with CHF and sinus rhythm derive a clinically important benefit from digoxin (with a 95% confidence interval of 1/33 to 1/5).

CNS-related subjective symptoms during treatment with beta 1-adrenoceptor antagonists (atenolol, metoprolol): two double-blind placebo controlled studies

1. Whilst a number of studies have investigated whether metoprolol and atenolol, the most widely used beta 1-adrenoceptor antagonists, differ with regard to CNS-related subjective symptoms, few placebo-controlled studies using standardised questionnaires have been performed. 2. In the present report, the findings of two randomised, double-blind, cross-over studies in healthy volunteers are presented. The subjects were treated with placebo and atenolol (100 mg once daily) (Study 1) and metoprolol (100 mg once daily) and placebo (Study 2). 3. Subjective experiences were evaluated using a standardised instrument, the Minor Symptoms Evaluation-profile (MSE-profile), which was filled in 4, 8 and 24 h after intake of the tablets. A Type A questionnaire was also completed by the subjects. 4. At 4 h both metoprolol and atenolol were found to affect negatively vitality and contentment, but these effects had declined after 8 h. A significant adverse effect on sleep was shown for atenolol compared with placebo, while no negative effect was observed for metoprolol. No significant differences were found in relation to Type A behaviour and beta-adrenoceptor blockade. The number of subjects with Type A personality was, however, low. 5. The results of the studies indicate that the subjective symptoms of the beta 1-adrenoceptor blockers are mild, and that the effects appear consistently with the recognised pharmacokinetic profiles of the two drugs.

Development and testing of a new measure of health status for clinical trials in heart failure

The authors developed a new measure of subjective health status for patients with heart failure. Eighty-eight patients with heart failure were asked about the impact of their condition on 123 items related to physical and emotional function. The most frequently chosen and important items were included in a 16-item Chronic Heart Failure Questionnaire (CHQ) that examines dyspnea during daily activities, fatigue, and emotional function. The CHQ was tested in a controlled trial of digoxin in heart failure patients in sinus rhythm. When administered serially to 25 patients in the run-in phase of the trial, the CHQ proved reproducible. Subsequently, CHQ results distinguished those who reported improvement or deterioration from those who did not. The CHQ showed moderate correlations with patient global ratings, walk test scores, and clinical assessments of heart failure. The authors conclude that the CHQ may be useful for measuring health status in clinical trials in heart failure.

Why different trials on digitalis give conflicting data

Taking a careful look at each of the outcomes measured in randomized, controlled trials of digoxin suggest that discrepancies in results may be more apparent than real. Digoxin does work, but clinically important benefit is restricted to a relatively small proportion of congestive heart failure (CHF) patients. The play of chance, the dose of digoxin used, and the severity of heart failure in patients enrolled in the studies are other factors that may explain the variability in results that were observed. A systematic examination of the sort undertaken here is likely to help resolve apparent difference in outcomes of clinical trials of new (and old) therapies in CHF patients.

A controlled trial of digoxin in congestive heart failure

Because of conflicting results from studies examining the usefulness of digoxin in congestive heart failure (CHF) patients in sinus rhythm, a cross-over trial was conducted in which 20 patients received 7 weeks of digoxin titrated to a level of 1.54 to 2.56 nmol/liter and 7 weeks of matched placebo. The order of treatments was determined by random allocation and patients, clinicians and research staff were blind to allocation. In patients with deteriorating condition, the treatment period was terminated and outcome measures were obtained. If deterioration occurred during the first period, the patient was crossed over without the code being broken. Seven patients required premature termination of study periods because of increasing symptoms of CHF. All 7 were taking placebo at the time (p = 0.016). Small differences in dyspnea (p = 0.044), walking test score (p = 0.055), clinical assessment of CHF (p = 0.036) and ejection fraction (p = 0.004) favored the digoxin treatment group. Patients with more severe CHF were more likely to benefit from digoxin administration. It was concluded that oral digoxin, in doses titrated to produce a serum level of 1.54 to 2.56 nmol/liter, improved quality of life and functional exercise capacity in some patients with CHF in sinus rhythm.

Self-assessed disability in patients with arthrosis of the hip joint. Reliability of the Swedish version of the Nottingham Health Profile

The study aimed to describe self-assessed disability, using the Nottingham Health Profile (NHP), in patients with arthrosis of the hip joint, to test the reliability of the Swedish version of the NHP, and to compare disability perceived by the patient with the Charnley/d'Aubignet score. The NHP was administered twice to 73 patients, waiting for total hip replacement. Pain, energy, sleep, and mobility were severely affected. The correlations between subjective and objective scores were, apart from pain, moderate. The two test administrations correlated highly. In conclusion, the NHP is a reliable instrument, which may provide valuable supplementary information in the assessment of disability.

Recruitment experience in clinical trials: literature summary and annotated bibliography

A literature review was conducted to determine what problems exist in accruing adequate numbers of patients for clinical trials. Accrual rates are often not clearly reported, and most studies report that the time period for accrual was extended. Delays in recruitment have an impact on costs and workload throughout the trial. Other problems with the recruitment outcomes include miscalculations in the number of eligible participants in the total population, variations in yield from different types of recruitment sources, and level of community awareness. Planning for recruitment should be part of the overall trial design. Ideally, recruitment planning should be conducted in harmony between the national and local levels. Local community members should be involved. Data-based management of recruitment is necessary and should include a comprehensive data monitoring system with strong administrative support at both central and local levels. Recruitment goals and provisions for corrective action if recruitment lags should be included. Socioeconomic characteristics and attitudes of patients and physicians should be considered in recruitment efforts because they can affect patient participation during all phases of the study.

Determining optimal therapy--randomized trials in individual patients

Although the treatment of an individual patient in routine clinical practice has been likened to an experiment, the method is so susceptible to bias that we have come to demand multi-patient, double-blind, randomized controlled trials on matters of efficacy. Unfortunately, such trials have not or cannot be carried out for many clinical disorders; even when they have been executed their results may be difficult to extrapolate to individual patients. To resolve this problem, we have begun to use double-blind randomized trials in which a single patient undergoes a series of pairs of treatments, consisting of one active and one placebo or alternative treatment per pair, with the order determined by random allocation. Appropriate treatment targets (signs, symptoms, or laboratory tests) are used as the measure of efficacy, and the trial is continued until efficacy is established or disproved. We describe such a trial, which resulted in a dramatically beneficial modification of treatment in a patient with partially reversible airflow limitation. We have established a clinical service that facilitates the widespread use of the method in our community.