Evidence Synthesis for Complex Interventions Using Meta-Regression Models

A goal of evidence synthesis for trials of complex interventions is to inform the design or implementation of novel versions of complex interventions by predicting expected outcomes with each intervention version. Conventional aggregate data meta-analyses of studies comparing complex interventions have limited ability to provide such information. We argue that evidence synthesis for trials of complex interventions should forgo aspirations of estimating causal effects and instead model the response surface of study results to 1) summarize the available evidence and 2) predict the average outcomes of future studies or in new settings. We illustrate this modeling approach using data from a systematic review of diabetes quality improvement (QI) interventions involving at least 1 of 12 QI strategy components. We specify a series of meta-regression models to assess the association of specific components with the posttreatment outcome mean and compare the results to conventional meta-analysis approaches. Compared with conventional approaches, modeling the response surface of study results can better reflect the associations between intervention components and study characteristics with the posttreatment outcome mean. Modeling study results using a response surface approach offers a useful and feasible goal for evidence synthesis of complex interventions that rely on aggregate data.

Reduced Compared With Traditional Schedules for Routine Antenatal Visits: A Systematic Review

OBJECTIVE

To assess differences in maternal and child outcomes in studies comparing reduced routine antenatal visit schedules with traditional schedules.

DATA SOURCES

A search was conducted of PubMed, Cochrane databases, EMBASE, CINAHL, and ClinicalTrials.gov through February 12, 2022, searching for antenatal (prenatal) care, pregnancy, obstetrics, telemedicine, remote care, smartphones, telemonitoring, and related terms, as well as primary study designs. The search was restricted to high-income countries.

METHODS OF STUDY SELECTION

Double independent screening was done in Abstrackr for studies comparing televisits and in-person routine antenatal care visits for maternal, child, health care utilization, and harm outcomes. Data were extracted into SRDRplus with review by a second researcher.

TABULATION, INTEGRATION, AND RESULTS

Five randomized controlled trials and five nonrandomized comparative studies compared reduced routine antenatal visit schedules with traditional schedules. Studies did not find differences between schedules in gestational age at birth, likelihood of being small for gestational age, likelihood of a low Apgar score, likelihood of neonatal intensive care unit admission, maternal anxiety, likelihood of preterm birth, and likelihood of low birth weight. There was insufficient evidence for numerous prioritized outcomes of interest, including completion of the American College of Obstetricians and Gynecologists-recommended services and patient experience measures.

CONCLUSION

The evidence base is limited and heterogeneous and allowed few specific conclusions. Reported outcomes included, for the most part, standard birth outcomes that do not have strong plausible biological connection to structural aspects of antenatal care. The evidence did not find negative effects of reduced routine antenatal visit schedules, which may support implementation of fewer routine antenatal visits. However, to enhance confidence in this conclusion, future research is needed, particularly research that includes outcomes of most importance and relevance to changing antenatal care visits.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO, CRD42021272287.

Televisits Compared With In-Person Visits for Routine Antenatal Care: A Systematic Review

OBJECTIVE

To compare benefits and harms of televisits and in-person visits in people receiving routine antenatal care.

DATA SOURCES

A search was conducted of PubMed, Cochrane databases, EMBASE, CINAHL, and ClinicalTrials.gov through February 12, 2022, for antenatal (prenatal) care, pregnancy, obstetrics, telemedicine, remote care, smartphones, telemonitoring, and related terms, as well as primary study designs. The search was restricted to high-income countries.

METHODS OF STUDY SELECTION

Double independent screening was done in Abstrackr for studies comparing televisits and in-person routine antenatal care visits for maternal, child, health care utilization, and harm outcomes. Data were extracted into SRDRplus with review by a second researcher.

TABULATION, INTEGRATION, AND RESULTS

Two randomized controlled trials, four nonrandomized comparative studies, and one survey compared visit types between 2004 and 2020, three of which were conducted during the coronavirus disease 2019 (COVID-19) pandemic. Number, timing, and mode of televisits and who provided care varied across studies. Low-strength evidence from studies comparing hybrid (televisits and in-person visits) and all in-person visits did not indicate differences in rates of neonatal intensive care unit admission of the newborn (summary odds ratio [OR] 1.02, 95% CI 0.82-1.28) or preterm births (summary OR 0.93, 95% CI 0.84-1.03). However, the studies with stronger, although still statistically nonsignificant, associations between use of hybrid visits and preterm birth compared the COVID-19 pandemic and prepandemic eras, confounding the association. There is low-strength evidence that satisfaction with overall antenatal care was greater in people who were pregnant and receiving hybrid visits. Other outcomes were sparsely reported.

CONCLUSION

People who are pregnant may prefer hybrid televisits and in-person visits. Although there is no evidence of differences in clinical outcomes between hybrid visits and in-person visits, the evidence is insufficient to evaluate most outcomes.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO, CRD42021272287.

Quality improvement strategies for diabetes care: Effects on outcomes for adults living with diabetes

BACKGROUND

There is a large body of evidence evaluating quality improvement (QI) programmes to improve care for adults living with diabetes. These programmes are often comprised of multiple QI strategies, which may be implemented in various combinations. Decision-makers planning to implement or evaluate a new QI programme, or both, need reliable evidence on the relative effectiveness of different QI strategies (individually and in combination) for different patient populations.

OBJECTIVES

To update existing systematic reviews of diabetes QI programmes and apply novel meta-analytical techniques to estimate the effectiveness of QI strategies (individually and in combination) on diabetes quality of care.

SEARCH METHODS

We searched databases (CENTRAL, MEDLINE, Embase and CINAHL) and trials registers (ClinicalTrials.gov and WHO ICTRP) to 4 June 2019. We conducted a top-up search to 23 September 2021; we screened these search results and 42 studies meeting our eligibility criteria are available in the awaiting classification section.

SELECTION CRITERIA

We included randomised trials that assessed a QI programme to improve care in outpatient settings for people living with diabetes. QI programmes needed to evaluate at least one system- or provider-targeted QI strategy alone or in combination with a patient-targeted strategy. - System-targeted: case management (CM); team changes (TC); electronic patient registry (EPR); facilitated relay of clinical information (FR); continuous quality improvement (CQI). - Provider-targeted: audit and feedback (AF); clinician education (CE); clinician reminders (CR); financial incentives (FI). - Patient-targeted: patient education (PE); promotion of self-management (PSM); patient reminders (PR). Patient-targeted QI strategies needed to occur with a minimum of one provider or system-targeted strategy.

DATA COLLECTION AND ANALYSIS

We dual-screened search results and abstracted data on study design, study population and QI strategies. We assessed the impact of the programmes on 13 measures of diabetes care, including: glycaemic control (e.g. mean glycated haemoglobin (HbA1c)); cardiovascular risk factor management (e.g. mean systolic blood pressure (SBP), low-density lipoprotein cholesterol (LDL-C), proportion of people living with diabetes that quit smoking or receiving cardiovascular medications); and screening/prevention of microvascular complications (e.g. proportion of patients receiving retinopathy or foot screening); and harms (e.g. proportion of patients experiencing adverse hypoglycaemia or hyperglycaemia). We modelled the association of each QI strategy with outcomes using a series of hierarchical multivariable meta-regression models in a Bayesian framework. The previous version of this review identified that different strategies were more or less effective depending on baseline levels of outcomes. To explore this further, we extended the main additive model for continuous outcomes (HbA1c, SBP and LDL-C) to include an interaction term between each strategy and average baseline risk for each study (baseline thresholds were based on a data-driven approach; we used the median of all baseline values reported in the trials). Based on model diagnostics, the baseline interaction models for HbA1c, SBP and LDL-C performed better than the main model and are therefore presented as the primary analyses for these outcomes. Based on the model results, we qualitatively ordered each QI strategy within three tiers (Top, Middle, Bottom) based on its magnitude of effect relative to the other QI strategies, where 'Top' indicates that the QI strategy was likely one of the most effective strategies for that specific outcome. Secondary analyses explored the sensitivity of results to choices in model specification and priors.  Additional information about the methods and results of the review are available as Appendices in an online repository. This review will be maintained as a living systematic review; we will update our syntheses as more data become available.

MAIN RESULTS

We identified 553 trials (428 patient-randomised and 125 cluster-randomised trials), including a total of 412,161 participants. Of the included studies, 66% involved people living with type 2 diabetes only. Participants were 50% female and the median age of participants was 58.4 years. The mean duration of follow-up was 12.5 months. HbA1c was the commonest reported outcome; screening outcomes and outcomes related to cardiovascular medications, smoking and harms were reported infrequently. The most frequently evaluated QI strategies across all study arms were PE, PSM and CM, while the least frequently evaluated QI strategies included AF, FI and CQI. Our confidence in the evidence is limited due to a lack of information on how studies were conducted.  Four QI strategies (CM, TC, PE, PSM) were consistently identified as 'Top' across the majority of outcomes. All QI strategies were ranked as 'Top' for at least one key outcome. The majority of effects of individual QI strategies were modest, but when used in combination could result in meaningful population-level improvements across the majority of outcomes. The median number of QI strategies in multicomponent QI programmes was three.  Combinations of the three most effective QI strategies were estimated to lead to the below effects:  - PR + PSM + CE: decrease in HbA1c by 0.41% (credibility interval (CrI) -0.61 to -0.22) when baseline HbA1c < 8.3%; - CM + PE + EPR: decrease in HbA1c by 0.62% (CrI -0.84 to -0.39) when baseline HbA1c > 8.3%;  - PE + TC + PSM: reduction in SBP by 2.14 mmHg (CrI -3.80 to -0.52) when baseline SBP < 136 mmHg; - CM + TC + PSM: reduction in SBP by 4.39 mmHg (CrI -6.20 to -2.56) when baseline SBP > 136 mmHg;  - TC + PE + CM: LDL-C lowering of 5.73 mg/dL (CrI -7.93 to -3.61) when baseline LDL < 107 mg/dL; - TC + CM + CR: LDL-C lowering by 5.52 mg/dL (CrI -9.24 to -1.89) when baseline LDL > 107 mg/dL. Assuming a baseline screening rate of 50%, the three most effective QI strategies were estimated to lead to an absolute improvement of 33% in retinopathy screening (PE + PR + TC) and 38% absolute increase in foot screening (PE + TC + Other).

AUTHORS' CONCLUSIONS

There is a significant body of evidence about QI programmes to improve the management of diabetes. Multicomponent QI programmes for diabetes care (comprised of effective QI strategies) may achieve meaningful population-level improvements across the majority of outcomes. For health system decision-makers, the evidence summarised in this review can be used to identify strategies to include in QI programmes. For researchers, this synthesis identifies higher-priority QI strategies to examine in further research regarding how to optimise their evaluation and effects. We will maintain this as a living systematic review.

Prehabilitation for Total Knee or Total Hip Arthroplasty: A Systematic Review

ABSTRACT

We sought to systematically review the evidence on the benefits and harms of prehabilitation interventions for patients who are scheduled to undergo elective, unilateral total knee arthroplasty or total hip arthroplasty surgery for the treatment of primary osteoarthritis. We searched PubMed, Embase, The Cochrane Central Register of Controlled Trials, CINAHL, PsycINFO, Scopus, and ClinicalTrials.gov from January 1, 2005, through May 3, 2021. We selected for inclusion randomized controlled trials and adequately adjusted nonrandomized comparative studies of prehabilitation programs reporting performance-based, patient-reported, or healthcare utilization outcomes. Three researchers extracted study data and assessed risk of bias, verified by an independent researcher. Experts in rehabilitation content and complex interventions independently coded rehabilitation interventions. The team assessed strength of evidence. While large heterogeneity across evaluated prehabilitation programs limited strong conclusions, evidence from 13 total knee arthroplasty randomized controlled trials suggest that prehabilitation may result in increased strength and reduced length of stay and may not lead to increased harms but may be comparable in terms of pain, range of motion, and activities of daily living (all low strength of evidence). There was no evidence or insufficient evidence for all other outcomes after total knee arthroplasty. Although there were six total hip arthroplasty randomized controlled trials, there was no evidence or insufficient evidence for all total hip arthroplasty outcomes.

Rehabilitation for Total Hip Arthroplasty: A Systematic Review

ABSTRACT

We sought to determine the comparative benefits and harms of rehabilitation interventions for patients who have undergone elective, unilateral THA surgery for the treatment of primary osteoarthritis. We searched PubMed, Embase, The Cochrane Register of Clinical Trials, CINAHL, PsycINFO, Scopus, and ClinicalTrials.gov from January 1, 2005, through May 3, 2021. We included randomized controlled trials and adequately adjusted nonrandomized comparative studies of rehabilitation programs reporting performance-based, patient-reported, or healthcare utilization outcomes. Three researchers extracted study data and assessed risk of bias, verified by an independent researcher. Experts in rehabilitation content and complex interventions independently coded rehabilitation interventions. The team assessed strength of evidence. Large heterogeneity across evaluated rehabilitation programs limited conclusions. Evidence from 15 studies suggests that diverse rehabilitation programs may not differ in terms of risk of harm or outcomes of pain, strength, activities of daily living, or quality of life (all low strength of evidence). Evidence is insufficient for other outcomes. In conclusion, no differences in outcomes were found between different rehabilitation programs after THA. Further evidence is needed to inform decisions on what attributes of rehabilitation programs are most effective for various outcomes.

Rehabilitation for Total Knee Arthroplasty: A Systematic Review

ABSTRACT

We sought to determine the comparative benefit and harm of rehabilitation interventions for patients who have undergone elective, unilateral total knee arthroplasty for the treatment of primary osteoarthritis. We searched PubMed, Embase, The Cochrane Register of Clinical Trials, CINAHL, PsycINFO, Scopus, and ClinicalTrials.gov from January 1, 2005, through May 3, 2021. We included randomized controlled trials and adequately adjusted nonrandomized comparative studies of rehabilitation programs reporting performance-based, patient-reported, or healthcare utilization outcomes. Three researchers extracted study data and assessed risk of bias, verified by an independent researcher. The team assessed strength of evidence. Evidence from 53 studies randomized controlled trials suggests that various rehabilitation programs after total knee arthroplasty may lead to comparable improvements in pain, range of motion, and activities of daily living. Rehabilitation in the acute phase may lead to increased strength but result in similar strength when delivered in the postacute phase. No studies reported evidence of risk of harms due to rehabilitation delivered in the acute period after total knee arthroplasty; risk of harms among various postacute rehabilitation programs seems comparable. All findings were of low strength of evidence. Evaluation of rehabilitation after total knee arthroplasty needs a systematic overhaul to sufficiently guide future practice or research including the use of standardized intervention components and core outcomes.

Pharmacotherapy interventions for adolescent co-occurring substance use and mental health disorders: a systematic review

BACKGROUND

Co-occurring mental health and substance use (SU) disorders among adolescents are common, with two-thirds of adolescents who seek SU treatment also requiring support for mental health. Primary care physicians play a key role in the pharmacological treatment of mental health disorders among adolescents, however, little is known about the impact of these treatments on SU outcomes.

OBJECTIVES

This systematic review summarizes the evidence regarding commonly used pharmacotherapy interventions for mental health and their impact on adolescent SU.

METHODS

Literature searches were conducted across five databases as part of a larger systematic review of adolescent SU interventions. Studies were screened for eligibility by two researchers, and study data were extracted regarding study design, patient and treatment characteristics and results. Risk of bias analyses and qualitative syntheses were completed to evaluate the strength of the evidence and the impact of pharmacotherapy on SU outcomes.

RESULTS

Ten randomized controlled trials exploring seven pharmacotherapies met criteria for inclusion. All studies had low to moderate risk of bias. Four studies evaluated pharmacotherapy for co-occurring depression and SU, three evaluated attention deficit hyperactivity disorder and SU, and three evaluated bipolar disorder and SU. Five of the 10 studies also included a behavioural intervention. We found no evidence that pharmacotherapy for co-occurring mental health diagnoses impacted SU.

CONCLUSION

Family medicine clinicians prescribing pharmacotherapy for mental health should be aware that additional interventions will likely be needed to address co-occurring SU.

Diagnostic Imaging and Medical Management of Acute Left-Sided Colonic Diverticulitis : A Systematic Review

BACKGROUND

Clinicians need to better understand the value of computed tomography (CT) imaging and nonsurgical treatment options to manage acute left-sided colonic diverticulitis.

PURPOSE

To evaluate CT imaging, outpatient treatment of uncomplicated diverticulitis, antibiotic treatment, and interventional radiology for patients with complicated diverticulitis.

DATA SOURCES

MEDLINE, Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews, Embase, CINAHL, and ClinicalTrials.gov from 1 January 1990 through 16 November 2020.

STUDY SELECTION

Existing systematic reviews of CT imaging accuracy, as well as randomized trials and adjusted nonrandomized comparative studies reporting clinical or patient-centered outcomes.

DATA EXTRACTION

6 researchers extracted study data and risk of bias, which were verified by an independent researcher. The team assessed strength of evidence across studies.

DATA SYNTHESIS

Based on moderate-strength evidence, CT imaging is highly accurate for diagnosing acute diverticulitis. For patients with uncomplicated acute diverticulitis, 6 studies provide low-strength evidence that initial outpatient and inpatient management have similar risks for recurrence or elective surgery, but they provide insufficient evidence regarding other outcomes. Also, for patients with uncomplicated acute diverticulitis, 5 studies comparing antibiotics versus no antibiotics provide low-strength evidence that does not support differences in risks for treatment failure, elective surgery, recurrence, posttreatment complications, and other outcomes. Evidence is insufficient to determine choice of antibiotic regimen (7 studies) or effect of percutaneous drainage (2 studies).

LIMITATIONS

The evidence base is mostly of low strength. Studies did not adequately assess heterogeneity of treatment effect.

CONCLUSION

Computed tomography imaging is accurate for diagnosing acute diverticulitis. For patients with uncomplicated diverticulitis, no differences in outcomes were found between outpatient and inpatient care. Avoidance of antibiotics for uncomplicated acute diverticulitis may be safe for most patients. The evidence is too sparse for other evaluated questions.

PRIMARY FUNDING SOURCE

Agency for Healthcare Research and Quality and American College of Physicians. (PROSPERO: CRD42020151246).

Effectiveness of quality improvement strategies for type 1 diabetes in children and adolescents: a systematic review protocol

Introduction: Optimal glycaemic control is often a challenge in children and adolescents with type 1 diabetes (T1D). Implementation of patient, clinician or organisation-targeted quality improvement (QI) strategies has been proven to be beneficial in terms of improving glycaemic outcomes in adults living with diabetes. This review aims to assess the effectiveness of such QI interventions in improving glycaemic control, care delivery, and screening rates in children and adolescents with T1D. Methods and analysis: MEDLINE, EMBASE, CINAHL and Cochrane CENTRAL databases will be searched for relevant studies up to January 2021. Trial registries, ClinicalTrials.gov and ICTRP, will also be explored for any ongoing trials of relevance. We will include trials which examine QI strategies as defined by a modified version of the Cochrane Effective Practice and Organisation of Care 2015 Taxonomy in children (<18 years) with a diagnosis of T1D. The primary outcome to be assessed is glycated haemoglobin (HbA1c), although a range of secondary outcomes relating to clinical management, adverse events, healthcare engagement, screening rates and psychosocial parameters will also be assessed. Our primary intention is to generate a best-evidence narrative to summarise and synthesise the resulting studies. If a group of studies are deemed to be highly similar, then a meta-analysis using a random effects model will be considered. Cochrane Risk of Bias 1.0 tool will be applied for quality assessment. All screening, data extraction and quality assessment will be performed by two independent researchers. Dissemination: The results of this review will be disseminated through peer-reviewed publication in order to inform invested partners (e.g., Paediatric Endocrinologists) on the potential of QI strategies to improve glycaemic management and other related health outcomes in children with T1D, thereby guiding best practices in the outpatient management of the disorder. PROSPERO registration number: CRD42021233974 (28/02/2021).

Management of primary headaches during pregnancy, postpartum, and breastfeeding: A systematic review

BACKGROUND

Primary headaches (migraine, tension headache, cluster headache, and other trigeminal autonomic cephalgias) are common in pregnancy and postpartum. It is unclear how to best and most safely manage them.

OBJECTIVE

We conducted a systematic review (SR) of interventions to prevent or treat primary headaches in women who are pregnant, attempting to become pregnant, postpartum, or breastfeeding.

METHODS

We searched Medline, Embase, Cochrane CENTRAL, CINAHL, ClinicalTrials.gov, Cochrane Database of SRs, and Epistemonikos for primary studies of pregnant women with primary headache and existing SRs of harms in pregnant women regardless of indication. No date or language restrictions were applied. We assessed strength of evidence (SoE) using standard methods.

RESULTS

We screened 8549 citations for studies and 2788 citations for SRs. Sixteen studies (mostly high risk of bias) comprising 14,185 patients (total) and 26 SRs met the criteria. For prevention, we found no evidence addressing effectiveness. Antiepileptics, venlafaxine, tricyclic antidepressants, benzodiazepines, β-blockers, prednisolone, and oral magnesium may be associated with fetal/child adverse effects, but calcium channel blockers and antihistamines may not be (1 single-group study and 11 SRs; low-to-moderate SoE). For treatment, combination metoclopramide and diphenhydramine may be more effective than codeine for migraine or tension headache (1 randomized controlled trial; low SoE). Triptans may not be associated with fetal/child adverse effects (8 nonrandomized comparative studies; low SoE). Acetaminophen, prednisolone, indomethacin, ondansetron, antipsychotics, and intravenous magnesium may be associated with fetal/child adverse effects, but low-dose aspirin may not be (indirect evidence; low-to-moderate SoE). We found insufficient evidence regarding non-pharmacologic treatments.

CONCLUSIONS

For prevention of primary headache, calcium channel blockers and antihistamines may not be associated with fetal/child adverse effects. For treatment, combination metoclopramide and diphenhydramine may be more effective than codeine. Triptans and low-dose aspirin may not be associated with fetal/child adverse effects. Future research should identify effective and safe interventions in pregnancy and postpartum.

Behavior Change Techniques in Continuing Professional Development

Continuing professional development (CPD) is a widely used and evolving set of complex interventions that seeks to update and improve the knowledge, skills, and performance of health care professionals to ultimately improve patient care and outcomes. While synthesized evidence shows CPD in general to be effective, effects vary, in part due to variation in CPD interventions and limited understanding of CPD mechanisms of action. We introduce two behavioral science tools-the Behavior Change Technique Taxonomy version 1 and the Theoretical Domains Framework-that can be used to characterize the content of CPD interventions and the determinants of behaviour potentially targeted by the interventions, respectively. We provide a worked example of the use of these tools in coding the educational content of 43 diabetes quality improvement trials containing clinician education as part of their multicomponent intervention. Fourteen (of a possible 93; 15%) behavior change techniques were identified in the clinician education content of the quality improvement trials, suggesting a focus of addressing the behavioral determinants beliefs about consequences, knowledge, skills, and social influences, of diabetes care providers' behavior. We believe that the Behavior Change Technique Taxonomy version 1 and Theoretical Domains Framework offer a novel lens to analyze the CPD content of existing evidence and inform the design and evaluation of future CPD interventions.

The effectiveness and safety of emergency department short stay units: a rapid review

Emergency department overcrowding is a serious and ongoing issue across Canada. Short stay units (SSUs) have emerged as a potentially useful strategy for managing overcrowding in emergency departments. Members of The Ottawa Hospital senior management team contemplating the introduction of an SSU to help alleviate emergency department overcrowding approached our rapid response service to conduct a rapid review on the safety and effectiveness of SSUs. This paper presents the process for conducting this review, its findings, and the end-user report generated for the senior management team and other stakeholders.

Physiotherapy secretion removal techniques in people with spinal cord injury: a systematic review

OBJECTIVE

To address whether secretion removal techniques increase airway clearance in people with chronic spinal cord injury (SCI).

DATA SOURCES AND STUDY SELECTION

MEDLINE/PubMed, CINAHL, EMBASE, and PsycINFO were searched from inception to May 2009 for population keywords (spinal cord injury, paraplegia, tetraplegia, quadriplegia) paired with secretion removal-related interventions and outcomes. Inclusion criteria for articles were a research study, irrespective of design, that examined secretion removal in people with chronic SCI published in English.

REVIEW METHODS

Two reviewers determined whether articles met the inclusion criteria, abstracted information, and performed a quality assessment using PEDro or Downs and Black criteria. Studies were then given a level of evidence based on a modified Sackett scale.

RESULTS

Of 2416 abstracts and titles retrieved, 24 met the inclusion criteria. Subjects were young (mean, 31 years) and 84% were male. Most evidence was level 4 or 5 and only 2 studies were randomized controlled trials. Three reports described outcomes for secretion removal techniques in addition to cough, whereas most articles examined the immediate effects of various components of cough. Studies examining insufflation combined with manual assisted cough provided the most consistent, high-level evidence. Compelling recent evidence supports the use of respiratory muscle training or electrical stimulation of the expiratory muscles to facilitate airway clearance in people with SCI.

CONCLUSION

Evidence supporting the use of secretion removal techniques in SCI, while positive, is limited and mostly of low level. Treatments that increase respiratory muscle force show promise as effective airway clearance techniques.

Effects of exercise training and inspiratory muscle training in spinal cord injury: a systematic review

OBJECTIVE

To provide a systematic review of the studies assessing exercise training and inspiratory muscle training (IMT) in individuals for the improved respiratory function of patients with spinal cord injury (SCI).

METHODS

Thirteen studies (5 exercise training, 8 IMT) were identified. Articles were scored for their methodological quality using the Physiotherapy Evidence Database scores and Downs and Black tools for randomized and nonrandomized studies, respectively. Conclusions were based on the most rigorously executed studies using Sackett's levels of evidence.

RESULTS

Study comparison was compromised by diverse research designs; small sample sizes; and heterogeneity of studied populations, protocols, and outcome measures. Based on current literature, there is level 2 evidence supporting exercise training as an intervention to improve respiratory strength and endurance and level 4 evidence to support exercise training as an intervention that might improve resting and exercising respiratory function in people with SCI. There is level 4 evidence to support IMT as an intervention that might decrease dyspnea and improve respiratory function in people with SCI.

CONCLUSIONS

There are insufficient data to strongly support the use of exercise training or IMT for improved respiratory function in people with SCI. There is some evidence of efficacy of both regimens; however, the evidence is not of the best possible quality.

Review of randomized clinical trials of drug-eluting stents for the prevention of in-stent restenosis

Drug-eluting stents (DESs) have shown significant promise at reducing rates of restenosis and subsequent revascularization compared with bare metal stents (BMSs). The purpose of this report is to provide a systematic review of the randomized clinical trials that have evaluated the efficacy and safety of DESs. A total of 28 randomized clinical trials were identified: 21 comparing a DES (sirolimus, paclitaxel, ABT-578, actinomycin, everolimus, or 7-hexanoyltaxol) with a BMS and 7 comparing a DES with another DES (sirolimus vs paclitaxel). Early sirolimus and polymeric paclitaxel studies in low-risk populations demonstrated marked reductions in restenosis according to angiographic and clinical parameters, compared with BMSs. These promising findings led to the more recent evaluations of DESs in higher risk patients in controlled and head-to-head comparisons. In these subsequent trials, sirolimus and paclitaxel DESs continued to exceed the therapeutic potential of BMSs, with a slight but consistent angiographic advantage being observed with the sirolimus DESs.