Cluster-randomisierte Studien: eine wichtige Methode in der allgemeinmedizinischen Forschung

Ready for SDM- evaluation of an interprofessional training module in shared decision making - A cluster randomized trial

OBJECTIVE

Ready for SDM was developed in Norway as a comprehensive modularized curriculum for health care providers (HCP). The current study evaluated the efficacy of one of the modules, a 2-hour interprofessional SDM training designed to enhance SDM competencies.

METHODS

A cluster randomized controlled trial was conducted with eight District Psychiatric Centres randomized to wait-list control (CG) or intervention group (IG). Participants and trainers were not blinded to their allocation. The IG received a 2-hour didactic and interactive training, using video examples. The primary outcome was the agreement between the participants' and an expert assessment of patient involvement in a video recorded consultation. The SDM-knowledge score was a secondary outcome.

RESULTS

Compared to the CG (n = 65), the IG (n = 69) judged involvement behavior in a communication example more accurately (mean difference of weighted T, adjusted for age and gender:=-0.098, p = 0.028) and demonstrated better knowledge (mean difference=-0.58; p = 0.014). A sensitivity analysis entering a random effect for cluster turned out not significant.

CONCLUSION

The interprofessional group training can improve HCPs' SDM-competencies.

PRACTICE IMPLICATIONS

Addressing interprofessional teams using SDM communication training could supplement existing SDM training approaches. More research is needed to evaluate the training module's effects as a component of large-scale implementation of SDM.

Effect Evaluation of Sahtak bi Sahnak, a Lebanese Secondary School-Based Nutrition Intervention: A Cluster Randomised Trial

Objective

To evaluate the effectiveness of Sahtak bi Sahnak on dietary knowledge and adherence to dietary guidelines in Lebanese adolescents.

Design/setting

A cluster randomised controlled trial was conducted in public and private secondary schools located in urban and rural regions in Lebanon.

Participants

Sixteen secondary schools including 1,572 adolescents were randomly assigned to the intervention (n = 739) or control group (n = 833).

Intervention

Sahtak bi Sahnak is an educational school-based intervention dedicated to improving dietary adherence to nutritional guidelines, increasing the level of dietary knowledge, and preventing the development of obesity during adolescence. It was systematically designed based on the Intervention Mapping framework. The total length of the intervention was around seven educational sessions, until all of the 11 lessons were covered. Each education session lasted 20-40 min.

Main Outcome Measures

Dietary knowledge and adherence levels were measured at baseline and post-intervention using validated questionnaires.

Statistical Analysis

Multivariate multilevel regression models were used to examine intervention effects on outcomes, controlled for background characteristics (i.e., age, gender, location, type of school, grade, BMI z-score).

Results

The intervention group showed significant improvements in total dietary knowledge (B = 12.74, p < 0.001) and intake of healthy items (B = 1.89, p < 0.001), compared to the control group. Intake of unhealthy items decreased significantly (B = -1.43, p < 0.001), compared to the control group. These results were adjusted for age, gender, type of school, location, BMI z-score, study group, and score at baseline.

Conclusion and Implications

Sahtak bi Sahnak is an effective and culturally appropriate school-based intervention for targeting diet among a variety of Lebanese adolescents.

The efficacy of an educational movie to improve pain and dysfunctional behavior in school children: A randomized controlled trial

BACKGROUND

Chronic pain in children is a serious issue, therefore calling for effective prevention/intervention measures. This study aimed to evaluate the efficacy of an educational movie on pain knowledge in school children in general and on pain-related behaviours and pain intensity in those who are affected by chronic pain. Regarding those affected, the association between pain knowledge and intensity, as well as the potential mediating effect of pain-related behaviours, were investigated.

METHODS

Recruited from four schools, N = 381 students (51.7% female; M_age  = 11.4, SD = 0.95) participated, of which n = 108 reported chronic pain. Each school was randomly allocated to the intervention or control group (cluster-randomization). At two time points spaced 4-5 weeks apart, students provided information on their pain knowledge, pain-related behaviour (passive pain coping, pain-related disability, missed school days, medication use) and pain intensity. After the first assessment, students in the intervention group watched an educational movie. Multilevel linear models for all outcomes were calculated as well as a mediation analysis.

RESULTS

Pain knowledge increased significantly in the intervention group (β = 2.76 [95% CI 2.20, 3.31]). However, no significant time-by-group interactions were found for pain-related behaviour or pain intensity. The mediation model identified that the indirect effect of pain knowledge on pain intensity was mediated by pain-related behaviour (β = -0.18, p = 0.014 and β = 0.38, p < 0.001, respectively).

CONCLUSIONS

Educational movies may be an effective tool for educating students about pain management. However, the knowledge gained may not be sufficient to improve pain behaviour and intensity overall.

SIGNIFICANCE

A 10-min educational movie on chronic pain management was tested in school children (N = 381). Following the intervention, knowledge of chronic pain concepts was statistically greater in the intervention group compared to the control group not watching the movie. Furthermore, a mediation model theoretically determined whether an association between pain knowledge and pain intensity exists, and whether this is explained by level of dysfunctional pain-related behaviorisms. Full mediation was confirmed.

RubiN - continuous care in regional networks: a study protocol for a prospective controlled trial

Background

The health care situation of geriatric patients is often multifaceted, complex and often overlaps with social living conditions. Due to the lack of cross-sectoral and interprofessional health care geriatric patients often, receive insufficient care. Only a holistic view enables a comprehensive evaluation of the complex health risks, but also the potential to preserve the health of geriatric patients. The implementation of cross-sectoral, multi-professional case management could reduce the gaps in care, improve the autonomy of the geriatric patients in their own homes, and allow them to retain it as long as possible.

The “RubiN” project examines the effects of multi-professional, cross-sectoral and assessment-based case management on the quality of the care of geriatric patients. The results of the study aim to show whether geriatric patients receive better care using case management than patients who receive standard health care. In addition, data on the effects of case management on practices of general practitioners (GP), the satisfaction with the care concept amongst the case managers, patients and relatives will be collected. Furthermore, a health economic analysis will be carried out.

Methods

The project is designed as a prospective controlled study and compares geriatric patients from practice networks in different regions in Germany. Inclusion criteria are: Age ≥ 70 years and care requirements from two different care complexes (identified with the screening instrument ‘Angelina’-questionnaire). The intervention is the use of a geriatric case management, where health care is organised based on patient-specific care requirements. Five practice networks of physicians will implement the intervention (n = 3200 patients) and three practice networks will serve as the control group (n = 1200 patients). The primary endpoint is the ability to manage activities of daily living, measured using the Barthel Index. The patients in the intervention group receive geriatric case management and the patients in the control networks receive standard care (“care as usual”). The analysis of the primary data, which is pseudonymised, occurs according to the intention-to-treat principle. For this purpose, the endpoints will be analysed using a group comparison after 12 months. For the health economic analysis, secondary data from the statutory health insurance providers will be included in the analysis, in addition to the primary data. Data for the analysis of the effects the concept has on the GP practices as well as on the satisfaction of the project participants will be collected with questionnaires and interviews with experts.

Discussion

The implementation of cross-sectoral and interdisciplinary geriatric case management has been a topic of discussion for years, whereby positive effects have already been-shown. This planned study will be the first evaluation of the effect of case management for geriatric patients with a very large sample. In addition, the effects of case management on the GP practices and also on the relatives of the geriatric patients will be shown. It is intended that the study results pave the way for a widespread implementation of this concept.

Trial registration

German Clinical Trials Register, ID: DRKS00016642. Registered on 29 October 2019 - Retrospectively registered.

Adherence Measures for Patients with Metastatic Castration-Resistant Prostate Cancer Treated with Abiraterone Acetate plus Prednisone: Results of a Prospective, Cluster-Randomized Trial

Simple Summary

We report the final results of a multicenter, prospective, 2-arm trial in a real world setting for patients with metastatic castration resistant prostate cancer. A number of 675 patients were allocated by center-based cluster-randomization to arm A with adherence enhancing measures or arm B without adherence enhancing measures. Our study reveals a generally high medication adherence in patients with mCRPC with no clear difference between Arm A and Arm B. Our results confirm the benefit of Abiraterone acetate plus Prednisolone in terms of effectiveness and quality of life in a real world setting.

Abstract

Residual androgen production causes tumor progression in metastatic, castration-resistant prostate cancer (mCRPC) patients. Abiraterone acetate (AA), a prodrug of abiraterone, is an oral CYP-17 inhibitor that blocks androgen production. It was hypothesized that adherence-enhancing measures (AEM) might be beneficial for mCRPC patients receiving abiraterone acetate plus prednisone (AA + P). This multicenter, prospective, 2-arm trial allocated mCRPC patients who were progressive after docetaxel-based chemotherapy or asymptomatic/mildly symptomatic after failure of an androgen deprivation therapy to Arm A (with AEM) or Arm B (without AEM) by center-based cluster-randomization. The primary objective was to assess the influence of AEM on discontinuation rates and medication adherence in mCRPC patients treated with AA + P. A total of 360 patients were allocated to Arm A, and 315 patients to Arm B. At month 3, the rate of treatment discontinuation, not due to disease progression or the start of new cancer therapy, was low in both arms (A: 9.0% vs. B: 7.3%, OR = 1.230). Few patients had a medium/low Morisky Medication Adherence Scale (MMAS-4) score (A: 6.4% vs. B: 9.1%, OR = 0.685). The results obtained did not suggest any clear adherence difference between Arm A and Arm B. In patients with mCRPC taking AA + P medication, adherence seemed to be generally high.

[Educational intervention to improve diagnostic accuracy regarding psychological morbidity in general practice]

INTRODUCTION

The aim of this pilot study was to evaluate the effectiveness of a complex educational intervention to improve the diagnostic competencies of general practitioners (GPs) regarding the detection of depression, anxiety and somatization.

METHODS

Cluster-randomized controlled pilot study with six practices each in the intervention group and in the control group. Psychological morbidity was determined by patient self-report using the Patient Health Questionnaire (PHQ-D). GPs rated the extent of psychological morbidity on a numerical rating scale from 0 (no co-morbidity) to 10 (maximum) of the individual patient after the consultation, independent of the reason for encounter.

RESULTS

364 patients participated. There were moderate correlations between GP rating and the PHQ scales (Spearman correlation between 0.27 and 0.42). There was no significant difference between intervention and control group. Diagnostic accuracy of the GPs, as determined with areas under the curves (AUCs), ranged between 0.52 (95%KI 0.30-0.73) and 0.84 (95%KI 0.67-1.00). The AUCs showed significant heterogeneity (Cochran Q=25.0; p<0.01). The regression analysis with 'presence of psychological disorder' (in PHQ) as the dependent variable showed that longer duration of doctor-patient-relationship was negatively associated with psychological morbidity (OR 0.96; 95%KI 0.92-0.99; p=0.01). There was a significant interaction between the factors 'time of doctor-patient relationship' and 'GP rating' (ß=0.02; OR 1.02, 95%KI 1.01-1.03; p<0.001), pointing towards increasing diagnostic accuracy when patients are known for a longer time.

DISCUSSION

We found no significant effect regarding the educational intervention. The GPs' estimation regarding psychological morbidity correlated significantly with the self-rating of the patients on PHQ scales. However, there was a considerable inter-individual variation between the GPs' diagnostic accuracy. The diagnostic estimation improved with increasing duration of doctor-physician relationship.

CONCLUSION

A one-time educational intervention seems not to be sufficient to improve diagnostic competencies in the detection of psychological morbidity. The considerable variation of the diagnostic accuracy might explain why 'one-size-fits-all' educational interventions will not help improve diagnostic competencies.

Piloting and evaluating feasibility of a training program to improve patient safety for inter-professional inpatient care teams - study protocol of a cluster randomized controlled trial

Background

Improving patient safety is a major goal in healthcare systems worldwide. There are several international training programs to improve patient safety, but they are often focused on single topics and professions. Therefore, one inter-professional training program for inpatient care teams, which combines key areas of patient safety (Teamwork, Error management and Patient involvement), was developed by our research group. In the present study we aim to (1) pilot this training program by comparing two different training formats (e-learning only versus blended learning) with a waiting control group and (2) evaluate the feasibility of the intervention.

Methods and analysis

(1) To pilot the intervention a cluster randomized controlled trial will be performed at three study sites. Therefore, an e-learning group and a blended learning group will be compared to a waiting control group at three points of assessment; (2) The feasibility of the intervention will be evaluated using qualitative methods. We will conduct problem-focused individual interviews as part of the post-intervention measurement in order to collect information on acceptance, implementation, promoting factors and barriers from the staffs’ perspective.

Discussion

The study puts forth a training program which has the potential to improve patient safety in inpatient care. Members of inter-professional inpatient care teams can receive systematic training in three competencies which are central to patient safety management. Thus, we expect the greatest improvement in staff Safety-related behavior regarding Teamwork, Error management and Patient involvement as well as Subjectively perceived patient safety in the blended learning group. In addition, the development of an optimal implementation strategy can foster implementation of the intervention in healthcare practice. Consequently, the intervention could be used continuously and comprehensively for advanced training of hospital staff.

Trial registration

The study has been registered in the German Register of Clinical Trials (DRKS-ID: DRKS00012818). Registered on August 8, 2017.

Electronic supplementary material

The online version of this article (10.1186/s13063-019-3448-7) contains supplementary material, which is available to authorized users.

Psychological and work-related outcomes after inpatient multidisciplinary rehabilitation of chronic low back pain: a prospective randomized controlled trial

Background

This study investigated the long-term effects (12 months post-rehabilitation) of a standard inpatient multidisciplinary rehabilitation program for patients with chronic low back pain (CLBP), in which a control group (CG) received pain competence training and an intervention group (IG) received combined pain competence and depression prevention training.

Methods

In this prospective control group study with cluster-block randomization, a total of n = 583 patients were included into per protocol analyses. To examine the effects of rehabilitation on depressive symptoms, pain self-efficacy, and work ability, patients were stratified in repeated-measures analyses of variance by treatment condition (IG vs. CG), level of depressive symptoms (low vs. high), and time of assessment (pre, post, 6, and 12 months after rehabilitation). The impact of each treatment on pain-related days of sick leave (DSL; dichotomized into ≤ vs. > 2 weeks) was determined separately by conducting non-parametric analyses. Multiple imputations (n = 1225) confirmed the results. Effects were interpreted if clinical significance was given.

Results

Only patients with high levels of depressive symptoms showed long-term improvements in depressive symptoms and self-efficacy. Long-term improvements in work ability index and mental work ability item were restricted to the IG. Furthermore, long-term effects on pain-related DSL were ascertained by per protocol and multiple imputation analyses only for the IG.

Conclusions

Patients with high levels of depressive symptoms showed improvements in depressive symptoms and self-efficacy, supporting the psychological effectiveness of both interventions. However, the beneficial long-term effects of rehabilitation on work ability and pain-related DSL among the IG support implementation of combined pain competence and depression prevention training.

Trial registration

DRKS00015465 (German Clinical Trial Register DRKS); date of registration: 03.09.2018.

Electronic supplementary material

The online version of this article (10.1186/s40359-019-0282-3) contains supplementary material, which is available to authorized users.

The Range and Scientific Value of Randomized Trials

BACKGROUND

The randomized, controlled trial (RCT) is the gold standard of scientific evidence for the attribution of clinical effects (benefits and harms) to medical interventions. Many different designs for RCTs have been developed in order to counter legitimate critical objections and to better adapt the trials to the continually changing challenges that face clinical research.

METHODS

The diversity and adaptability of randomized trial designs are presented and discussed on the basis of a selective literature review and specific illustrative examples.

RESULTS

A wide range of RCT designs enables adaptation to special research tasks and clinical framework conditions. These include (among others) crossover trials, n=1 trials, factorial RCT designs, and cluster-randomized trials. In addition, adaptive designs such as modern platform trials and pragmatic RCTs with simplified clinical questions and less severely restricted patient groups make broad recruitment of patients possible even in routine clinical practice.

CONCLUSION

Only the randomized allocation of subjects to the treatment and control groups, which is the defining property of RCTs, can adequately ensure that traits of the subjects which might disturb or bias a comparison of two or more medical interventions, will be evenly distributed across groups, regardless of whether these traits are known or unknown. The methodological variants and further elaborations of the RCT that are discussed here will help protect patients by enabling the assessment of the benefits and harms of medical methods and products on the basis of robust evidence even in the present era of rapid innovation.

Micronutrient-Fortified Milk and Academic Performance among Chinese Middle School Students: A Cluster-Randomized Controlled Trial

Many children suffer from nutritional deficiencies that may negatively affect their academic performance. This cluster-randomized controlled trial aimed to test the effects of micronutrient-fortified milk in Chinese students. Participants received either micronutrient-fortified (n = 177) or unfortified (n = 183) milk for six months. Academic performance, motivation, and learning strategies were estimated by end-of-term tests and the Motivated Strategies for Learning Questionnaire. Blood samples were analyzed for micronutrients. In total, 296 students (82.2%) completed this study. Compared with the control group, students in the intervention group reported higher scores in several academic subjects (p < 0.05), including languages, mathematics, ethics, and physical performance at the end of follow-up. Students in the intervention group showed greater self-efficacy and use of cognitive strategies in learning, and reported less test anxiety (p < 0.001). Moreover, vitamin B₂ deficiency (odds ratio (OR) = 0.18, 95% confidence interval (CI): 0.11~0.30) and iron deficiency (OR = 0.34, 95% CI: 0.14~0.81) were less likely in the students of the intervention group, whereas vitamin D, vitamin B₁₂, and selenium deficiencies were not significantly different. “Cognitive strategy” had a partial mediating effect on the test scores of English (95% CI: 1.26~3.79) and Chinese (95% CI: 0.53~2.21). Our findings suggest that micronutrient-fortified milk may improve students’ academic performance, motivation, and learning strategies.

Shared decision making PLUS - a cluster-randomized trial with inpatients suffering from schizophrenia (SDM-PLUS)

BACKGROUND

Shared decision making (SDM) is a model of how doctors and patients interact with each other. It aims at changing the traditional power asymmetry between doctors and patients by strengthening the exchange of information and the decisional position of the patient. Although SDM is generally welcomed by mental health patients as well as by mental health professionals its implementation in routine care, especially in the more acute settings, is still lacking. SDM-PLUS has been developed as an approach that addresses both patients and mental health professionals and aims at implementing SDM even for the very acutely ill patients.

METHODS

The SDM-PLUS study will be performed as a matched-pair cluster-randomized trial in acute psychiatric wards. On wards allocated to the intervention group personnel will receive communication training (addressing how to implement SDM for various scenarios) and patients will receive a group intervention addressing patient skills for SDM. Wards allocated to the control condition will continue treatment as usual. A total sample size of 276 patients suffering from schizophrenia or schizoaffective disorder on 12 wards is planned. The main outcome parameter will be patients' perceived involvement in decision making during the inpatient stay measured with the SDM-Q-9 questionnaire. Secondary objectives include the therapeutic relationship and long term outcomes such as medication adherence and rehospitalization rates. In addition, process measures and qualitative data will be obtained to allow for the analysis of potential barriers and facilitators of SDM-PLUS. The primary analysis will be a comparison of SDM-Q-9 sum scores 3 weeks after study inclusion (or discharge, if earlier) between the intervention and control groups. To assess the effect of the intervention on this continuous primary outcome, a random effects linear regression model will be fitted with ward (cluster) as a random effect term and intervention group as a fixed effect.

DISCUSSION

This will be the first trial examining the SDM-PLUS approach for patients with schizophrenia or schizoaffective disorder in very acute mental health inpatient settings. Within the trial a complex intervention will be implemented that addresses both patients and health care staff to yield maximum effects.

TRIAL REGISTRATION

German Clinical Trials Register DRKS00010880 . Registered 09 August 2016.

Cluster-randomized Studies in Educational Research: Principles and Methodological Aspects

An increasing number of studies are being performed in educational research to evaluate new teaching methods and approaches. These studies could be performed more efficiently and deliver more convincing results if they more strictly applied and complied with recognized standards of scientific studies. Such an approach could substantially increase the quality in particular of prospective, two-arm (intervention) studies that aim to compare two different teaching methods. A key standard in such studies is randomization, which can minimize systematic bias in study findings; such bias may result if the two study arms are not structurally equivalent. If possible, educational research studies should also achieve this standard, although this is not yet generally the case. Some difficulties and concerns exist, particularly regarding organizational and methodological aspects. An important point to consider in educational research studies is that usually individuals cannot be randomized, because of the teaching situation, and instead whole groups have to be randomized (so-called "cluster randomization"). Compared with studies with individual randomization, studies with cluster randomization normally require (significantly) larger sample sizes and more complex methods for calculating sample size. Furthermore, cluster-randomized studies require more complex methods for statistical analysis. The consequence of the above is that a competent expert with respective special knowledge needs to be involved in all phases of cluster-randomized studies. Studies to evaluate new teaching methods need to make greater use of randomization in order to achieve scientifically convincing results. Therefore, in this article we describe the general principles of cluster randomization and how to implement these principles, and we also outline practical aspects of using cluster randomization in prospective, two-arm comparative educational research studies.

Patient satisfaction with ambulatory care in Germany: effects of patient- and medical practice-related factors

Objective

The study aimed to illustrate the effect of the patients' sex, age, self-rated health and medical practice specialization on patient satisfaction.

Design

Secondary analysis of patient survey data using multilevel analysis (generalized linear mixed model, medical practice as random effect) using a sequential modelling strategy. We examined the effects of the patients' sex, age, self-rated health and medical practice specialization on four patient satisfaction dimensions: medical practice organization, information, interaction, professional competence.

Setting

The study was performed in 92 German medical practices providing ambulatory care in general medicine, internal medicine or gynaecology.

Participants

In total, 9888 adult patients participated in a patient survey using the validated 'questionnaire on satisfaction with ambulatory care-quality from the patient perspective [ZAP]'.

Main outcome measure(s)

We calculated four models for each satisfaction dimension, revealing regression coefficients with 95% confidence intervals (CIs) for all independent variables, and using Wald Chi-Square statistic for each modelling step (model validity) and LR-Tests to compare the models of each step with the previous model.

Results

The patients' sex and age had a weak effect (maximum regression coefficient 1.09, CI 0.39; 1.80), and the patients' self-rated health had the strongest positive effect (maximum regression coefficient 7.66, CI 6.69; 8.63) on satisfaction ratings. The effect of medical practice specialization was heterogeneous.

Conclusions

All factors studied, specifically the patients' self-rated health, affected patient satisfaction. Adjustment should always be considered because it improves the comparability of patient satisfaction in medical practices with atypically varying patient populations and increases the acceptance of comparisons.

Soziale Unterstützung als Baustein eines betrieblichen Programms zur Sport- und Bewegungsförderung

Zusammenfassung. Untersucht wurde die spezifische Wirkung der Interventionstechnik „Planung sportbezogener sozialer Unterstützung“ (PssU) im Rahmen eines betrieblichen Programms zur Sportförderung („MoVo-work“). Die Mitarbeitenden (N = 69) wurden cluster-randomisiert 2 Gruppen zugeordnet: die Interventionsgruppe (IG) erhielt MoVo-work mit dem Modul PssU, die Kontrollgruppe (KG) MoVo-work ohne dieses Modul. Sportaktivität und soziale Unterstützung wurden vor (T1) und nach der Intervention (T2) erhoben, sowie nach 6 Wochen (T3) und 6 Monaten (T4). In der IG nahm der Anteil der sportlich aktiven Personen beim Vergleich T1 – T3 um 24 % zu (p < .05); in der KG dagegen nur um 9 %. Auch beim Vergleich T1 – T4 war in der IG noch ein Zuwachs an sportlich aktiven Personen von 8 % festzustellen, wohingegen in der KG deren Anteil sogar um 3 % abnahm. Es fanden sich keine Gruppenunterschiede hinsichtlich der wahrgenommenen sozialen Unterstützung. Die Resultate zeigen, dass betriebliche Bewegungsförderungsprogramme substanziell davon profitieren können, wenn sie auch die Ebene der sozialen Unterstützung berücksichtigen.

Shared decision-making in antihypertensive therapy: a cluster randomised controlled trial

Background

Hypertension is one of the key factors causing cardiovascular diseases. A substantial proportion of treated hypertensive patients do not reach recommended target blood pressure values. Shared decision making (SDM) is to enhance the active role of patients. As until now there exists little information on the effects of SDM training in antihypertensive therapy, we tested the effect of an SDM training programme for general practitioners (GPs). Our hypotheses are that this SDM training (1) enhances the participation of patients and (2) leads to an enhanced decrease in blood pressure (BP) values, compared to patients receiving usual care without prior SDM training for GPs.

Methods

The study was conducted as a cluster randomised controlled trial (cRCT) with GP practices in Southwest Germany. Each GP practice included patients with treated but uncontrolled hypertension and/or with relevant comorbidity. After baseline assessment (T0) GP practices were randomly allocated into an intervention and a control arm. GPs of the intervention group took part in the SDM training. GPs of the control group treated their patients as usual. The intervention was blinded to the patients. Primary endpoints on patient level were (1) change of patients’ perceived participation (SDM-Q-9) and (2) change of systolic BP (24h-mean). Secondary endpoints were changes of (1) diastolic BP (24h-mean), (2) patients’ knowledge about hypertension, (3) adherence (MARS-D), and (4) cardiovascular risk score (CVR).

Results

In total 1357 patients from 36 general practices were screened for blood pressure control by ambulatory blood pressure monitoring (ABPM). Thereof 1120 patients remained in the study because of uncontrolled (but treated) hypertension and/or a relevant comorbidity. At T0 the intervention group involved 17 GP practices with 552 patients and the control group 19 GP practices with 568 patients. The effectiveness analysis could not demonstrate a significant or relevant effect of the SDM training on any of the endpoints.

Conclusion

The study hypothesis that the SDM training enhanced patients’ perceived participation and lowered their BP could not be confirmed. Further research is needed to examine the impact of patient participation on the treatment of hypertension in primary care.

Trial registration

German Clinical Trials Register (DRKS): DRKS00000125

[Manual for the design of non-drug trials in primary care, taking account of Good Clinical Practice (GCP) criteria]

In recent years studies not falling under the German Pharmaceutical Law ("non-drug trials") have also been increasingly expected to be conducted according to Good Clinical Practice (GCP) in order to ensure that uniform standards are maintained for data quality and patient safety. However, simple transfer of the GCP criteria is not always possible and often not useful. Given the fact that research questions regarding non-drug interventions are common in primary care (e.g., general practice), the "Network for Clinical Studies in General Practice" has developed a manual for planning and conducting non-drug trials. This manual is based on the GCP guideline, taking account of the conditions and circumstances in primary care settings. Both structure and relevant content of the manual are presented in the article. (As supplied by the authors).