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Christopher H Schmid

Publications and source records attributed to Christopher H Schmid.

At least 37 records · Page 2Linked to original sources
PubMed2004

Meta-regression detected associations between heterogeneous treatment effects and study-level, but not patient-level, factors.

OBJECTIVE: Two investigations evaluate Bayesian meta-regression for detecting treatment interactions. STUDY DESIGN AND SETTING: The first compares analyses of aggregate and individual patient data on 1,860 subjects from 11 trials testing angiotensin converting enzyme (ACE) inhibitors for nondiabetic kidney disease. The second explores meta-regression for detecting treatment interaction on 671 covariates, including the baseline risk, from 232 meta-analyses of binary outcomes compiled from the Cochrane Collaboration and the medical literature. RESULTS: In the ACE inhibitor study, treatment effects were homogeneous so meta-regression identified no interactions. Analysis of individual patient data using a multilevel model, however, discovered that treatment reduced glomerular filtration rate (GFR) more among patients with higher baseline proteinuria. The second investigation found meta-regression most effective for detecting treatment interactions with study-level factors in meta-analyses with >10 studies, heterogeneous treatment effects, or significant overall treatment effects. Under all three conditions, 46% of meta-regressions produced strong interactions (posterior probability >0.995) compared with 6% otherwise. Baseline risk was associated with the odds ratio in 6% of meta-analyses, half the rate found using maximum likelihood. CONCLUSION: Meta-regression can detect interactions of treatment with study-level factors when treatment effects are heterogeneous. Individual patient data are needed for patient-level factors and homogeneous effects.

Adult↗
PubMed2003

Association between estrogen receptor alpha gene variation and cardiovascular disease.

CONTEXT: Estrogen and related hormone therapies activate estrogen receptors, which in turn regulate genes for several cardiovascular disease (CVD) risk factors. Relatively little is known, however, about the impact of genetic variation in estrogen receptor alpha (ESR1) on CVD risk. OBJECTIVE: To investigate whether the ESR1 c.454-397T>C polymorphism is associated with CVD risk. DESIGN, SETTING, AND PARTICIPANTS: Prospective study of 1739 unrelated men and women from the population-based offspring cohort of the Framingham Heart Study, who were followed up from 1971 to 1998. MAIN OUTCOME MEASURES: Total atherosclerotic CVD events, defined as recognized or unrecognized myocardial infarction (MI), angina pectoris, coronary insufficiency, intermittent claudication, coronary heart disease death, or atherothrombotic stroke (n = 178); major atherosclerotic CVD, defined as recognized acute MI, coronary insufficiency, coronary heart disease death, or atherothrombotic stroke (n = 83); and recognized acute MI (n = 59). RESULTS: Twenty percent of participants (n = 352) were homozygous for the ESR1 c.454-397C allele. After adjustment for covariates (age, sex, body mass index, hypertension, diabetes mellitus, total cholesterol, high-density lipoprotein cholesterol, and cigarette smoking), the CC genotype was significantly associated with major atherosclerotic CVD, with an odds ratio of 2.0 (95% confidence interval [CI], 1.3-3.2; P =.004) compared with individuals with the CT or TT genotypes. Participants with the CC genotype had 3.0-fold greater odds of MI (95% CI, 1.7-5.2; P<.001) compared with those with the CT or TT genotype. The results remained significant when analyses were restricted to men; too few women had events to study them separately. CONCLUSIONS: Individuals with the common ESR1 c.454-397CC genotype have a substantial increase in risk of MI. Whether ESR1 c.454-397T>C is causally related to MI risk or in linkage disequilibrium with 1 or more causal variants remains to be determined. These findings support the importance of estrogen receptors in CVD susceptibility, especially in men. Estrogen receptor variation also has potential to explain recent conflicting data regarding the effects of hormone therapy on CVD susceptibility in women.

Cardiovascular Diseases↗
PubMed2003

Progression of chronic kidney disease: the role of blood pressure control, proteinuria, and angiotensin-converting enzyme inhibition: a patient-level meta-analysis.

BACKGROUND: Angiotensin-converting enzyme (ACE) inhibitors reduce blood pressure and urine protein excretion and slow the progression of chronic kidney disease. PURPOSE: To determine the levels of blood pressure and urine protein excretion associated with the lowest risk for progression of chronic kidney disease during antihypertensive therapy with and without ACE inhibitors. DATA SOURCES: 11 randomized, controlled trials comparing the efficacy of antihypertensive regimens with or without ACE inhibitors for patients with predominantly nondiabetic kidney disease. STUDY SELECTION: MEDLINE database search for English-language studies published between 1977 and 1999. DATA EXTRACTION: Data on 1860 nondiabetic patients were pooled in a patient-level meta-analysis. Progression of kidney disease was defined as a doubling of baseline serum creatinine level or onset of kidney failure. Multivariable regression analysis was performed to assess the association of systolic and diastolic blood pressure and urine protein excretion with kidney disease progression at 22 610 patient visits. DATA SYNTHESIS: Mean duration of follow-up was 2.2 years. Kidney disease progression was documented in 311 patients. Systolic blood pressure of 110 to 129 mm Hg and urine protein excretion less than 2.0 g/d were associated with the lowest risk for kidney disease progression. Angiotensin-converting enzyme inhibitors remained beneficial after adjustment for blood pressure and urine protein excretion (relative risk, 0.67 [95% CI, 0.53 to 0.84]). The increased risk for kidney progression at higher systolic blood pressure levels was greater in patients with urine protein excretion greater than 1.0 g/d (P < 0.006). CONCLUSION: Although reverse causation cannot be excluded with certainty, a systolic blood pressure goal between 110 and 129 mm Hg may be beneficial in patients with urine protein excretion greater than 1.0 g/d. Systolic blood pressure less than 110 mm Hg may be associated with a higher risk for kidney disease progression.

Angiotensin-Converting Enzyme Inhibitors↗
PubMed2003

Adjusting for publication bias in the presence of heterogeneity.

It is known that the existence of publication bias can influence the conclusions of a meta-analysis. Some methods have been developed to deal with publication bias, but issues remain. One particular method called 'trim and fill' is designed to adjust for publication bias. The method, which is intuitively appealing and comprehensible by non-statisticians, is based on a simple and popular graphical tool called the funnel plot. We present a simulation study designed to evaluate the behaviour of this method. Our results indicate that when the studies are heterogeneous (that is, when they estimate different effects), trim and fill may inappropriately adjust for publication bias where none exists. We found that trim and fill may spuriously adjust for non-existent bias if (i) the variability among studies causes some precisely estimated studies to have effects far from the global mean or (ii) an inverse relationship between treatment efficacy and sample size is introduced by the studies' a priori power calculations. The results suggest that the funnel plot itself is inappropriate for heterogeneous meta-analyses. Selection modelling is an alternative method warranting further study. It performed better than trim and fill in our simulations, although its frequency of convergence varied, depending on the simulation parameters.

Computer Simulation↗
PubMed2003

Time-dependent predictors of primary cardiac arrest in patients with acute myocardial infarction.

To understand predictors of cardiac arrest early in acute myocardial infarction (AMI), for the Thrombolytic Predictive Instrument, we developed a multivariable regression model predicting primary cardiac arrest using time-dependent variables based on a case-control study of emergency department (ED) patients with AMI: 65 cases with sudden cardiac arrest and 258 without cardiac arrest. Within the first hour of AMI symptom onset, adjusting for age, systolic blood pressure, serum potassium, and infarct size, increased risk of cardiac arrest was associated with electrocardiographic prolonged QTc interval and a greater sum of ST-segment elevation. After 1 hour, the effect of ST-segment elevation was much reduced and the effect of the QTc interval was reversed, so prolonged QTc appeared protective. Accordingly, for patients presenting 30 minutes after chest pain onset, compared with a QTc of 0.44, the risk for cardiac arrest for patients with QTc of 0.50 was more than doubled (odds ratio [OR] 2.20, 95% confidence intervals [CI] 1.17 to 4.13), whereas for those presenting after an hour, it was much lower (e.g., at 1.5 hours, OR 0.21, 95% CI 0.06 to 0.73). Patients presenting 30 minutes after chest pain onset with a sum of ST elevation of 20 mm had a threefold higher risk than patients with a sum of ST elevation of 5 mm (OR 3.37, 95% CI 1.83 to 6.20). However, if presenting 1.5 hours after chest pain onset, the risk was barely elevated (OR 1.18; 95% CI 1.09 to 1.29). Thrombolytic therapy was protective, halving the odds of cardiac arrest (OR 0.51, 95% CI 0.27 to 0.93). Thus, the relation of prolonged QTc interval and substantial ST segment elevation to cardiac arrest in AMI may be obscured because patients with these risks are more likely to die soon after AMI onset, before ED presentation, and are thereby unavailable for study. Those with prolonged QTc or substantial ST elevation who survive the initial 1.5-hour period are those less susceptible to these risks.

Aged↗
PubMed2003

Constructing a database of individual clinical trials for longitudinal analysis.

Individual patient data are often required to evaluate how patient-specific factors modify treatment effects. We describe our experience combining individual patient data from 1946 subjects in 11 randomized controlled trials evaluating the effect of angiotensin-enzyme converting (ACE) inhibitors for treating nondiabetic renal disease. We sought to confirm the results of our meta-analysis of group data on the efficacy of ACE inhibitors in slowing the progression of renal disease, as well as to determine whether any study or patient characteristics modified the beneficial effects of treatment. In particular, we wanted to find out if the mechanism of action of ACE inhibitors could be explained by adjusting for follow-up blood pressure and urine protein. Each trial site sent a database of multiple files and multiple records per patient containing longitudinal data of demographic, clinical, and medication variables to the data coordinating center. The databases were constructed in several different languages using different software packages with unique file formats and variable names. Over 4 years, we converted the data into a standardized database of more than 60,000 records. We overcame a variety of problems including inconsistent protocols for measurement of key variables; varying definitions of the baseline time; varying follow-up times and intervals; differing medication-reporting protocols; missing variables; incomplete, missing, and implausible data values; and concealment of key data in text fields. We discovered that it was easier and more informative to request computerized data files and merge them ourselves than to ask the investigators to abstract partial data from their files. Although combining longitudinal data from different trials based on different protocols in different languages is complex, costly, and time-intensive, analyses based on individual patient data are extremely informative. Funding agencies must be encouraged to provide support to collaborative groups combining databases.

Angiotensin-Converting Enzyme Inhibitors↗
PubMed2003

External validity of predictive models: a comparison of logistic regression, classification trees, and neural networks.

BACKGROUND AND OBJECTIVE: The utility of predictive models depends on their external validity, that is, their ability to maintain accuracy when applied to patients and settings different from those on which the models were developed. We report a simulation study that compared the external validity of standard logistic regression (LR1), logistic regression with piecewise-linear and quadratic terms (LR2), classification trees, and neural networks (NNETs). METHODS: We developed predictive models on data simulated from a specified population and on data from perturbed forms of the population not representative of the original distribution. All models were tested on new data generated from the population. RESULTS: The performance of LR2 was superior to that of the other model types when the models were developed on data sampled from the population (mean receiver operating characteristic [ROC] areas 0.769, 0.741, 0.724, and 0.682, for LR2, LR1, NNETs, and trees, respectively) and when they were developed on nonrepresentative data (mean ROC areas 0.734, 0.713, 0.703, and 0.667). However, when the models developed using nonrepresentative data were compared with models developed from data sampled from the population, LR2 had the greatest loss in performance. CONCLUSION: Our results highlight the necessity of external validation to test the transportability of predictive models.

Classification↗
PubMed2003

The impact of early transfer bias in a growth study among neonatal intensive care units.

BACKGROUND AND OBJECTIVE: Transfer of infants between hospitals or their discharge home may bias comparisons of the performance across neonatal intensive care units (NICUs). This study attempts to show the potential size of transfer bias in the context of a large cohort study and describe strategies for minimizing this type of bias. METHODS: To limit transfer bias in a neonatal growth study of extremely premature infants in six tertiary NICUs, we restricted eligibility to infants <30 weeks gestation at birth and substituted matched replacements for early transfers (infants transferred or discharged prior to day of life 16). RESULTS: The restriction strategy was successful, reducing the overall early transfer rate from 16.4 to 3.6% and the range of transfer rates among individual NICUs from 0.6-32.7% to 0-11.0%. Replacement by matched substitutes had a much smaller effect because of the small number of early transfers and our inability to match on all factors distinguishing early transfers. CONCLUSION: Sampling strategies to minimize infants lost to follow-up were more successful than replacement strategies in limiting transfer bias in a NICU growth study. Although complete elimination of bias is likely impossible, valid studies require efforts to minimize, quantify, and test the effect of transfer bias.

Bias↗
PubMed2003

Ethnic differences and determinants of proteinuria among South Asian subgroups in Pakistan.

BACKGROUND: Hypertension, diabetes, increasing age, and smoking are known risk factors for proteinuria. Prevalence of proteinuria is high in South Asians. However, ethnic subgroup differences and determinants of proteinuria within the South Asian population have not been explored. METHODS: The National Health Survey of Pakistan conducted between 1990 and 1994 was used to explore ethnic subgroup variation in proteinuria. Distinct ethnic subgroups, the Muhajir, the Punjabi, the Sindhi, the Pashtun, and the Baluchi, were defined by mother tongue. We report results in individuals aged >or=15 years (N = 9442). Proteinuria was defined as dipstick positive for protein on random urine sample. RESULTS: Increasing age, high consumption of meat, and presence of hypertension and diabetes were each independently associated with proteinuria. The age-standardized prevalence of proteinuria was 4.6% (4.2% to 5.1%) and varied among ethnic subgroups (P < 0.001). The highest was among the Sindhi (men 9.5%, women 10.3%), then the Muhajir (men 8.2%, women 4.7%), the Punjabi (men 3.2% women 3.5%), and lowest among the Baluchi (men 2.4%, women 4.2%) and the Pashtun (men 2.7%, women 1.2%). The ethnic differences persisted after adjusting for the above-mentioned sociodemographic, dietary, and clinical risk factors [adjusted odds ratio (OR) (95% CI)] were 6.42 (3.97 to 10.38) for the Sindhis, 3.58 (2.22 to 5.79) for the Muhajirs, 2.03 (1.25 to 3.29) for the Punjabis, and 1.75 (0.79 to 3.88) for the Baluchis compared to the Pashtuns). CONCLUSION: We conclude that unmeasured environmental or genetic factors account for ethnic variations in proteinuria, and deserve further study.

Adult↗
PubMed2003

The rate of progression of renal disease may not be slower in women compared with men: a patient-level meta-analysis.

BACKGROUND: Some studies suggest that progression of renal disease is slower in women than in men. However, other factors that are also associated with progression of renal disease have not always been taken into account. Therefore, we undertook this analysis to explore the independent association of renal disease progression with gender. METHODS: We analysed a pooled database of patients with non-diabetic renal disease enrolled in 11 randomized controlled trials evaluating the efficacy of angiotensin-converting enzyme inhibitors (ACEIs) for slowing renal disease progression. The primary end point was the combined outcome of doubling of baseline serum creatinine or onset of end-stage renal disease (ESRD). The secondary end point was the onset of ESRD alone. We performed multivariable Cox proportional hazards analysis to study the independent effect of gender on these end points after adjusting for baseline patient characteristics, and changes from baseline to follow-up systolic blood pressure (SBP) and urine protein (UP) excretion. RESULTS: The total number of patients was 1860: 645 (35%) females and 1215 (65%) males. Mean duration of follow-up was 2.2 years. The proportions randomized to ACEI (51%), mean baseline serum creatinine (2.2 mg/dl) and mean age (52 years) were similar for both genders. Mean baseline SBP was greater in women than in men: 151 vs 147 mmHg (P < 0.001). Mean baseline UP was significantly lower in women compared with men: 1.3 vs 2.1 g/day (P < 0.001). A total of 311 (16.7%) patients developed the primary end point, and 176 (9.5%) developed the secondary end point. The unadjusted relative risk (RR) with 95% confidence interval (CI) for the primary end point in women vs men was 0.98 (0.77-1.24). It became 1.32 (1.03-1.69) after adjusting for the baseline variables and interaction between ACEIs and baseline UP, and 1.36 (1.06-1.75) after adjusting for baseline variables and changes in SBP and UP during follow-up. Similar results were found for the outcome of ESRD. CONCLUSIONS: Our findings suggest that the rate of renal disease progression may not be slower, and may even be faster in women compared with men, after adjusting for other factors associated with a faster rate of progression. We caution that most women in our database were of post-menopausal age, and thus our findings may not extend to younger women.

Adult↗
PubMed2003

Ethnic subgroup differences in hypertension in Pakistan.

OBJECTIVE: Cardiovascular risks are globally elevated in South Asians, but this masks important ethnic subgroup differences in risk factors, such as hypertension, which have not been fully explored. We conducted this study to explore the variations in hypertension within ethnic subgroups among South Asians. DESIGN: Cross-sectional survey [National Health Survey of Pakistan (NHSP) (1990-1994)]. SETTING: Population based. PARTICIPANTS: A total of 9442 individuals aged 15 years or over. METHODS: Data on sociodemographic and clinical variables were collected. Distinct ethnic subgroups - Muhajir, Punjabi, Sindhi, Pashtun and Baluchi - were defined by mother tongue. MAIN OUTCOME MEASURE: Hypertension defined as systolic blood pressure >or= 140 mmHg or diastolic blood pressure >or= 90 mmHg, or currently receiving antihypertensive therapy. RESULTS: The age-standardized prevalence of hypertension was highest among Baluchis (25.3% in men and 41.4% in women), then Pashtuns (23.7% in men and 28.4% in women), Muhajirs (24.1% in men and 24.6% in women), and lowest among Punjabis (17.3% in men and 16.4% in women) and Sindhis (19.0% in men and 9.9% in women) (P = 0.001). While hypertension was more prevalent in urban (22.7%) versus rural dwellers (18.1%) [odds ratio (OR) 1.34; 95% confidence interval (CI), 1.20, 1.49], this difference was no longer significant after adjusting for body mass and waist circumference (OR 1.03; 95% CI, 0.91, 1.16). However, ethnic differences persisted after adjusting for major sociodemographic, dietary and clinical risk factors (unadjusted OR for Baluchi versus Sindhi, 2.92; 95% CI, 2.20-3.89; adjusted OR, 2.71; 95% CI, 1.97-3.75). CONCLUSIONS: A threefold difference in prevalence of hypertension exists between people of South Asian descent, which, unlike the urban/rural difference, cannot be accounted for by measured risk factors. Further study would provide valuable etiological and therapeutic clues.

Adolescent↗
PubMed2002

Correlation of quality measures with estimates of treatment effect in meta-analyses of randomized controlled trials.

CONTEXT: Specific features of trial quality may be associated with exaggeration or shrinking of the observed treatment effect in randomized studies. Therefore, assessment of trial quality is often used in meta-analysis. However, the degree to which specific quality measures are associated with treatment effects has not been well established across a broad range of clinical areas. OBJECTIVE: To determine if quality measures are associated with treatment effect size in randomized controlled trials (RCTs). DESIGN: Quality measures from published quality assessment scales were evaluated in RCTs included in meta-analyses from 4 medical areas (cardiovascular disease, infectious disease, pediatrics, and surgery). Included meta-analyses incorporated at least 6 RCTs, examined dichotomous outcomes, and demonstrated significant between-study heterogeneity in the odds ratio (OR) scale. MAIN OUTCOME MEASURES: Relative ORs comparing overall treatment effect (summary OR) of high vs low-quality studies, as determined by each quality measure, with relative ORs less than 1 indicating larger treatment effect in low-quality studies. RESULTS: Twenty-four quality measures were analyzed for 276 RCTs from 26 meta-analyses. Relative ORs of high vs low-quality studies for these quality measures ranged from 0.83 to 1.26; none was statistically significantly associated with treatment effect. The proportion of studies fulfilling specific quality measures varied widely in the 4 medical areas. In analyses limited to specific medical areas, placebo control, multicenter studies, study country, caregiver blinding, and statistical methods were significantly associated with treatment effect on 7 occasions. These relative ORs ranged from 0.40 to 1.74. However, the directions of these associations were not consistent. CONCLUSIONS: Individual quality measures are not reliably associated with the strength of treatment effect across studies and medical areas. Although use of specific quality measures may be appropriate in specific well-defined areas in which there is pertinent evidence, findings of associations with treatment effect cannot be generalized to all clinical areas or meta-analyses.

Data Interpretation, Statistical↗
PubMed2002

Individual patient- versus group-level data meta-regressions for the investigation of treatment effect modifiers: ecological bias rears its ugly head.

When performing a meta-analysis, interest often centres on finding explanations for heterogeneity in the data, rather than on producing a single summary estimate. Such exploratory analyses are frequently undertaken with published, study-level data, using techniques of meta-analytic regression. Our goal was to explore a real-world example for which both published, group-level and individual patient-level data were available, and to compare the substantive conclusions reached by both methods. We studied the benefits of anti-lymphocyte antibody induction therapy among renal transplant patients in five randomized trials, focusing on whether there are subgroups of patients in whom therapy might prove particularly beneficial. Allograft failure within 5 years was the endpoint studied. We used a variety of analytic approaches to the group-level data, including weighted least-squares regression (N=5 studies), logistic regression (N=628, the total number of subjects), and a hierarchical Bayesian approach. We fit logistic regression models to the patient-level data. In the patient-level analysis, we found that treatment was significantly more effective among patients with elevated (20 per cent or more) panel reactive antibodies (PRA) than among patients without elevated PRA. These patients comprise a small (about 15 per cent of patients) subgroup of patients that benefited from therapy. The group-level analyses failed to detect this interaction. We recommend using individual patient data, when feasible, to study patient characteristics, in order to avoid the potential for ecological bias introduced by group-level analyses.

Bias↗
PubMed2002

Is primary angioplasty for some as good as primary angioplasty for all?

OBJECTIVES: To investigate whether proper patient selection might allow most of the benefits of population-wide primary coronary angioplasty to be captured in a subgroup of high-risk patients. BACKGROUND: Despite growing evidence that angioplasty yields better outcomes, thrombolytic therapy remains the most common form of reperfusion therapy in acute myocardial infarction (AMI) because of limited capacity for primary coronary angioplasty at most hospitals. METHODS: We used a validated logistic regression model, based on individual patient characteristics, to estimate the distribution of mortality risk in a community-based sample of 1,058 patients who received reperfusion therapy for AMI. To estimate the benefits across different baseline risks, we examined the results of 10 randomized controlled trials using meta-regression techniques. RESULTS: Assuming a constant relative risk reduction, 68% of all mortality benefits in our community-based patient sample could be captured by treating only those patients in the highest quartile of mortality risk and 87% of the benefit could be captured by treating those in the highest half. Moreover, meta-regression of the results from the 10 clinical trials suggests that patients with a mortality risk of less than 2% may be unlikely to receive any mortality benefit. With this risk-benefit relationship, treatment of only the 39% of patients with the highest risk would yield equivalent mortality outcomes to population-wide angioplasty. CONCLUSION: Most of the incremental benefits of primary angioplasty can be achieved by treating high-risk patients. For these patients, thrombolytic therapy may be difficult to justify if nearby primary angioplasty is available. For most patients, however, thrombolytic therapy appears to be an effective alternative.

Adult↗
PubMed2002

Intersite differences in weight growth velocity of extremely premature infants.

OBJECTIVE: To explain differences in weight growth velocity of extremely premature infants among 6 level III neonatal intensive care units (NICUs). METHODS: In 6 NICUs, we studied 564 infants, stratified by gestational age (GA), who were first admissions, survivors, <30 weeks' GA at birth, and in the NICU at least 16 days. Case mix (eg, birth weight, GA, race, illness severity, prenatal steroids), exposure to medical practices/complications (eg, respiratory support, postnatal steroids, necrotizing enterocolitis, infection), and nutritional intake (kcal/kg/d and protein in g/kg/d) were collected and used to predict weight growth velocity between day 3 and day 28 (or discharge, if transferred early) in multiple linear regression models. RESULTS: Weight growth velocities varied significantly among the 6 NICUs. Adjustment for case mix and medical factors explained little of this variability, but additional control for calorie and especially protein intake accounted for much of the intersite variability. For the average infant, adjusted growth velocity ranged from 10.4 to 14.3 g/kg/d among the sites studied. The final predictive model, including case mix and medical and nutritional factors, explained 53% of the overall variance in growth velocity. Prolonged (> or =15 days) exposure to postnatal steroids and greater severity of illness both decreased growth velocity. The model predicted that adding 1 g/kg/d protein to the mean intake for our sample would increase growth by 4.1 g/kg/d. CONCLUSIONS: Variation in nutrition explained much of the difference in growth among the NICUs studied. Mean intake of calories and protein failed to meet recommended levels, and the average growth in only 1 NICU approximated intrauterine growth standards. Increasing nutritional intake into the recommended ranges, in particular of protein, may increase growth of extremely premature infants up to or above intrauterine rates.

Body Weight↗
PubMed2002

Self-management education for adults with type 2 diabetes: a meta-analysis of the effect on glycemic control.

OBJECTIVE: To evaluate the efficacy of self-management education on GHb in adults with type 2 diabetes. RESEARCH DESIGN AND METHODS: We searched for English language trials in Medline (1980-1999), Cinahl (1982-1999), and the Educational Resources Information Center database (ERIC) (1980-1999), and we manually searched review articles, journals with highest topic relevance, and reference lists of included articles. Studies were included if they were randomized controlled trials that were published in the English language, tested the effect of self-management education on adults with type 2 diabetes, and reported extractable data on the effect of treatment on GHb. A total of 31 studies of 463 initially identified articles met selection criteria. We computed net change in GHb, stratified by follow-up interval, tested for trial heterogeneity, and calculated pooled effects sizes using random effects models. We examined the effect of baseline GHb, follow-up interval, and intervention characteristics on GHb. RESULTS: On average, the intervention decreased GHb by 0.76% (95% CI 0.34-1.18) more than the control group at immediate follow-up; by 0.26% (0.21% increase - 0.73% decrease) at 1-3 months of follow-up; and by 0.26% (0.05-0.48) at > or = 4 months of follow-up. GHb decreased more with additional contact time between participant and educator; a decrease of 1% was noted for every additional 23.6 h (13.3-105.4) of contact. CONCLUSIONS: Self-management education improves GHb levels at immediate follow-up, and increased contact time increases the effect. The benefit declines 1-3 months after the intervention ceases, however, suggesting that learned behaviors change over time. Further research is needed to develop interventions effective in maintaining long-term glycemic control.

Adaptation, Psychological↗