for the other diseases studied. a subsequent letter to the editor claimed that disease management might nevertheless "satisfy buyers today, even if academics remain unconvinced". a 2008 systematic review and meta-analysis concluded that disease management for copd "modestly improved exercise capacity, health-related quality of life, and hospital admissions, but not all-cause mortality". a 2009 review of 27 studies "could not draw definitive conclusions about the effectiveness or cost-effectiveness of... asthma disease-management programs" for adults. a canadian systematic review published in 2009 found that home telehealth in chronic disease management may be cost-saving but that "the quality of the studies was generally low." researchers from the netherlands systematically reviewed 31 papers published 2007–09 and determined that the evidence that disease management programs for four diseases reduce healthcare expenditures is "inconclusive." a meta-analysis of randomized trials published through 2009 estimated that disease management for diabetes has "a clinically moderate but significant impact on hemoglobin a1c levels," with an absolute mean difference of 0.51% between experimental and control groups. a 2011 "meta-review" (systematic review of meta-analyses) of heart failure disease management programs found them to be of "mixed quality" in that they did not report important characteristics of the studies reviewed. a 2015 systematic review of randomised controlled trials examining the impact of chronic disease management programmes for adults with asthma, found that having a coordinated program approach with multiple health care professionals compared with usual care can positively impact on the severity of asthma, can improve lung function and also perceived quality of life. studies not reviewed in the aforementioned papers include the following: a u.k. study published in 2007 found certain improvements in the care of patients with coronary artery disease and heart failure (e.g., better management of blood pressure and cholesterol) if they received nurse-led disease management instead of usual care. in a 2007 canadian study, people were randomized to receive or not receive disease management for heart failure for a period of six months. emergency department visits, hospital readmissions, and all-cause deaths were no different in the two groups after 2.8 years of follow-up. a 2008 u.s. study found that nurse-led disease management for patients with heart failure was "reasonably cost-effective" per quality-adjusted life year compared with a "usual care group". a 2008 study from the netherlands compared no disease management with "basic" nurse-led disease management with "intensive" nurse-led disease management for patients discharged from the hospital with heart failure; it detected no significant differences in hospitalization and death for the three groups of patients. a retrospective cohort study from 2008 found that disease management did not increase the use of drugs recommended for patients after a heart attack. of 15 care coordination (disease management) programs followed for two years in a 2008 study, "few programs improved patient behaviors, health, or quality of care" and "no program reduced gross or net expenditures". after 18 months, a 2008 florida study found "virtually no overall impacts on hospital or emergency room (er) use, medicare expenditures, quality of care, or prescription drug use" for a disease management program. with minor exceptions, a paper published in 2008 did not find significant differences in outcomes among people with asthma randomly assigned to telephonic disease management, augmented disease management (including in-home respiratory therapist visits), or traditional care. a 2009 review by the centers for medicare and medicaid services of 35 disease management programs that were part of demonstration projects between 1999 and 2008 found that relatively few improved quality in a budget-neutral manner. in a 2009 randomized trial, high- and moderate-intensity disease management did not improve smoking cessation rates after 24 months compared with drug therapy alone. a randomized trial published in 2010 determined that disease management reduced a composite score of emergency department visits and hospitalizations among patients discharged from veterans administration hospitals for chronic obstructive pulmonary disease. a 2011 post-hoc analysis of the study's data estimated that the intervention produced a net cost savings of $593 per patient. a spanish study published in 2011 randomized 52 people hospitalized for heart failure to follow-up with usual care, 52 to home visits, 52 to telephone follow-up, and 52 to an in-hospital heart failure unit. after a median of 10.8 months of follow-up, there were no significant differences in hospitalization or mortality among the four groups. among 18- to 64-year-old people with chronic diseases receiving medicaid, telephone-based disease management in one group of members did not reduce ambulatory care visits, hospitalizations, or expenditures relative to a control group. furthermore, in this 2011 study, the group receiving disease management had a lower decrease in emergency department visits than the group not receiving disease management.