all italian citizens are covered by a government health insurance and are registered with a general practitioner ( gp ) . primary care for diabetes is provided by gps and diabetes outpatient clinics ( docs ) . patients can choose one of these two ways of accessing the health care system or they can be referred to docs by their gps . within the italian health care system this observational longitudinal study involved docs adopting an electronic medical record system for the routine management of outpatients . each center was asked to enroll up to 100 patients , selected among individuals having a scheduled visit during 6 months , using random sampling lists . eligible individuals were men and women patients with type 2 diabetes mellitus , aged 18 years , irrespective of diabetes treatment and duration . information on cv events that occurred during three years was collected on ad hoc case report forms ( supplementary fig . all the data were analyzed anonymously , and patients were identified only by a numeric code . patients were enrolled between january 2006 and november 2007 and followed up until september 2009 . the study was approved by local ethics committees of all participating centers . a quality - of - care summary score ( table 1 ) , developed and validated in a previous study ( 14 ) , was applied to the quasar population to confirm its ability to predict the incidence of major vascular events . quality - of - care scoring system ma , microalbuminuria ; arbs , angiotensin receptor blockers . the score includes those process and intermediate indicators for which a clear link with vascular complications was demonstrated and effective preventive strategies are available . for each item , the highest score was assigned when the desired goals was attained , whereas the lowest score was assigned when the patient was not treated for the specific condition despite elevated values or when the patient showed unsatisfactory values despite the treatment . monitoring hba1c , blood pressure , lipids , or microalbuminuria less frequently than once a year was attributed an intermediate scoring under the assumption that these parameters could be less frequently monitored in individuals with less severe diabetes and in better control . after having developed the score in the qued ( quality of care and outcomes in type 2 diabetes ) study , we have empirically tested this aspect in the quasar study , where we have also collected blood samples , which were centrally analyzed . from these data it emerged that patients monitored less frequently tended to have lower hba1c and lipid levels and were markedly less likely to have microalbuminuria . to avoid a strict dependence from the data , the scores attributed to each process and outcome measure were decided a priori and not based on weights derived from regression models applied to the data . overall , the quality score ranges between 0 and 40 , with a higher score reflecting better quality of care . the scoring system was applied to the data collected at study entry and tested as a predictor of incident cv events . indicators were calculated using the last information relative to the 12 months preceding the recruitment . because normal ranges for glycated hemoglobin varied among different centers , the percent change with respect to the upper normal value ( actual value / upper normal limit ) was estimated and multiplied by 6.0 . additional indicators , such as foot or eye examination , although representing key components of diabetes care , were not considered , since information was reported in nonstandardized format in medical records . the primary composite end point was represented by total cv events , including angina , myocardial infarction ( mi ) , stroke , transient ischemic attack , coronary revascularization procedures , lower - limb complications ( claudication , ulcer , gangrene , amputation , aortic - femoral revascularization procedures ) , and cv mortality . secondary end points were represented by major cv events ( nonfatal mi , nonfatal stroke , cv mortality ) , mi , cardiac revascularization procedures , stroke , lower - limb complications , cv deaths , and total deaths . mi was defined based on the presence of at least two of the following : 1 ) typical ischemic chest pain , pulmonary edema , syncope , or shock ; 2 ) development of pathological q - waves and/or appearance or disappearance of localized st - elevation followed by t - wave inversion in two or more of twelve standard electrocardiograph leads ; and 3 ) increase in the concentration of serum enzymes consistent with mi . stroke was defined on the basis of the presence of unequivocal signs or symptoms of focal or global neurologic deficit , with sudden onset , lasting more than 24 h , and considered of vascular origin . the following criteria were adopted to define cv death : death occurring within 28 days after the onset of the documented diagnosis of mi or stroke , in the absence of any other evident cause ; sudden deaths ; deaths from heart failure ; and all other deaths classified as cardiovascular ( international classification of disease , ninth edition , clinical modification ) . the absence of any evident noncardiovascular cause was sufficient to define a death as cardiovascular . all of the events were certified by the participating clinicians and were based on clinical documentation . patients were contacted by phone if their last visit to the center had occurred more than 6 months before . based on the results of the previous study , the quality score was categorized in three classes ; however , because of a general trend of improvements in the average quality of care in the last years , the cutoffs of the middle class were shifted ahead by 5 points ( < 15 , 1525 , > patients characteristics according to score classes were compared using the  test for categorical variables and the kruskal - wallis one - way anova for continuous variables . incidence rates ( ir ) by score classes were expressed in terms of events per 1,000 person - years . probabilities of cv event according to score classes were calculated using the kaplan - meier method and compared using the log - rank test . all reported p values are two - sided . to account for the multilevel nature of the data ( patients clustered within diabetes clinic ) , and to control simultaneously for the possible confounding effects of the different covariates , we used multilevel poisson regression models to investigate whether the score was an independent predictor of cv events incidence ( 15 ) . in multilevel analyses patient - related characteristics were tested as level 1 variables , whereas setting - related characteristics represented level 2 variables . the following patients characteristics were tested : age , sex , bmi , duration of diabetes and treatment , smoking , and history of previous cv event . the risk of cv events according to the score classes was expressed in terms of incidence rate ratio ( irr ) and 95% confidence intervals ( 95% cis ) , with a score of > 25 as the reference category . finally , we estimated the intraclass correlation coefficient ( icc ) using the score as dependent variable to evaluate the extent to which the score varies between centers as compared with within - center variation , taking patient case - mix into account ( 16 ) . the higher the icc , the greater the influence of the physician - level on the quality - of - care score . all italian citizens are covered by a government health insurance and are registered with a general practitioner ( gp ) . primary care for diabetes is provided by gps and diabetes outpatient clinics ( docs ) . patients can choose one of these two ways of accessing the health care system or they can be referred to docs by their gps . within the italian health care system this observational longitudinal study involved docs adopting an electronic medical record system for the routine management of outpatients . each center was asked to enroll up to 100 patients , selected among individuals having a scheduled visit during 6 months , using random sampling lists . eligible individuals were men and women patients with type 2 diabetes mellitus , aged 18 years , irrespective of diabetes treatment and duration . information on cv events that occurred during three years was collected on ad hoc case report forms ( supplementary fig . all the data were analyzed anonymously , and patients were identified only by a numeric code . patients were enrolled between january 2006 and november 2007 and followed up until september 2009 . a quality - of - care summary score ( table 1 ) , developed and validated in a previous study ( 14 ) , was applied to the quasar population to confirm its ability to predict the incidence of major vascular events . quality - of - care scoring system ma , microalbuminuria ; arbs , angiotensin receptor blockers . the score includes those process and intermediate indicators for which a clear link with vascular complications was demonstrated and effective preventive strategies are available . for each item , the highest score was assigned when the desired goals was attained , whereas the lowest score was assigned when the patient was not treated for the specific condition despite elevated values or when the patient showed unsatisfactory values despite the treatment . monitoring hba1c , blood pressure , lipids , or microalbuminuria less frequently than once a year was attributed an intermediate scoring under the assumption that these parameters could be less frequently monitored in individuals with less severe diabetes and in better control . after having developed the score in the qued ( quality of care and outcomes in type 2 diabetes ) study , we have empirically tested this aspect in the quasar study , where we have also collected blood samples , which were centrally analyzed . from these data it emerged that patients monitored less frequently tended to have lower hba1c and lipid levels and were markedly less likely to have microalbuminuria . to avoid a strict dependence from the data , the scores attributed to each process and outcome measure were decided a priori and not based on weights derived from regression models applied to the data . overall , the quality score ranges between 0 and 40 , with a higher score reflecting better quality of care . the scoring system was applied to the data collected at study entry and tested as a predictor of incident cv events . indicators were calculated using the last information relative to the 12 months preceding the recruitment . because normal ranges for glycated hemoglobin varied among different centers , the percent change with respect to the upper normal value ( actual value / upper normal limit ) was estimated and multiplied by 6.0 . additional indicators , such as foot or eye examination , although representing key components of diabetes care , were not considered , since information was reported in nonstandardized format in medical records . the primary composite end point was represented by total cv events , including angina , myocardial infarction ( mi ) , stroke , transient ischemic attack , coronary revascularization procedures , lower - limb complications ( claudication , ulcer , gangrene , amputation , aortic - femoral revascularization procedures ) , and cv mortality . secondary end points were represented by major cv events ( nonfatal mi , nonfatal stroke , cv mortality ) , mi , cardiac revascularization procedures , stroke , lower - limb complications , cv deaths , and total deaths . mi was defined based on the presence of at least two of the following : 1 ) typical ischemic chest pain , pulmonary edema , syncope , or shock ; 2 ) development of pathological q - waves and/or appearance or disappearance of localized st - elevation followed by t - wave inversion in two or more of twelve standard electrocardiograph leads ; and 3 ) increase in the concentration of serum enzymes consistent with mi . stroke was defined on the basis of the presence of unequivocal signs or symptoms of focal or global neurologic deficit , with sudden onset , lasting more than 24 h , and considered of vascular origin . the following criteria were adopted to define cv death : death occurring within 28 days after the onset of the documented diagnosis of mi or stroke , in the absence of any other evident cause ; sudden deaths ; deaths from heart failure ; and all other deaths classified as cardiovascular ( international classification of disease , ninth edition , clinical modification ) . the absence of any evident noncardiovascular cause was sufficient to define a death as cardiovascular . all of the events were certified by the participating clinicians and were based on clinical documentation . patients were contacted by phone if their last visit to the center had occurred more than 6 months before . based on the results of the previous study , the quality score was categorized in three classes ; however , because of a general trend of improvements in the average quality of care in the last years , the cutoffs of the middle class were shifted ahead by 5 points ( < 15 , 1525 , > 25 ) . patients characteristics according to score classes were compared using the  test for categorical variables and the kruskal - wallis one - way anova for continuous variables . incidence rates ( ir ) by score classes were expressed in terms of events per 1,000 person - years . probabilities of cv event according to score classes were calculated using the kaplan - meier method and compared using the log - rank test . all reported p values are two - sided . to account for the multilevel nature of the data ( patients clustered within diabetes clinic ) , and to control simultaneously for the possible confounding effects of the different covariates , we used multilevel poisson regression models to investigate whether the score was an independent predictor of cv events incidence ( 15 ) . in multilevel analyses patient - related characteristics were tested as level 1 variables , whereas setting - related characteristics represented level 2 variables . the following patients characteristics were tested : age , sex , bmi , duration of diabetes and treatment , smoking , and history of previous cv event . the risk of cv events according to the score classes was expressed in terms of incidence rate ratio ( irr ) and 95% confidence intervals ( 95% cis ) , with a score of > 25 as the reference category . finally , we estimated the intraclass correlation coefficient ( icc ) using the score as dependent variable to evaluate the extent to which the score varies between centers as compared with within - center variation , taking patient case - mix into account ( 16 ) . the higher the icc , the greater the influence of the physician - level on the quality - of - care score . the study was conducted in 67 diabetes clinics , and 5,181 patients were enrolled and followed up for a median of 28 months ( interquartile range 2431 ) . overall , 6.7% of the patients had a score of < 15 , 68.2% had a score between 15 and 25 , and 25.1% had a score of > 25 . patients with the lowest score had a longer diabetes duration , and a larger percentage of them were already treated with insulin as compared with patients in the other two score classes . patient characteristics according to quality - of - care score data are percentages or mean  sd . * p values refer to  for categorical variables and kruskal - wallis one - way anova for continuous variable . during the follow - up , 477 ( 9.2% ) patients developed one or more cv events . the cv event rate was strictly related to the score , being of 62.1 per 1,000 person - years in patients with a score of < 15 , 41.0 per 1,000 person - years in those with a score between 15 and 25 , and 36.7 per 1,000 person - years in those with a score of > 25 . unadjusted kaplan - meier curves show that a score of < 15 was associated with a significant higher likelihood to develop a cv event ( fig . multilevel analysis , adjusted for clustering , age , sex , bmi , duration of diabetes , smoking , and history of cv event , showed that the risk to develop a new cv event was 84% greater in patients with a score of < 15 ( irr = 1.84 ; 95% ci 1.292.62 ) and 17% higher in those with a score between 15 and 25 ( irr = 1.17 ; 95% ci 0.931.49 ) , as compared with those with a score of > 25 . a trend of increasing overall mortality according to the quality score was also documented , although statistical significance was not reached ( irr = 1.68 ; 95% ci 0.783.63 and irr = 1.35 ; 95% ci 0.832.21 for a score of < 15 and between 20 and 25 , respectively , compared with a score of > 25 ) . the same trend of association was found for most of the outcomes , although statistical significance was reached for lower limb complications only ( fig . the strong correlation between the score of quality of care and cv events was evident in patients without previous cv events as well as in those who had already experienced a previous event ( supplementary table a1 ) . risk of developing cv events according to quality of care score classes : results of multilevel analyses . data are crude incidence rates ( irs ) and multilevel irrs adjusted for age , sex , bmi , duration of diabetes , smoking , and history of previous cv event . the position of each square indicates the point estimate of the risk associated with a score of < 15 ( black squares ) , between 15 and 25 ( gray squares ) , and > 25 ( white squares ) . the latter represents the reference category . total cv events include angina , mi , stroke , transient ischemic attack , coronary revascularization procedures , lower - limb complications , cv deaths ;  major cv events include mi , stroke , and cv deaths ; lower - limb complications include claudication , ulcer , gangrene , amputation , and aortic - femoral revascularization procedures . finally , the mean quality score varied substantially across centers ( from 16.5  7.5 to 29.1  6.3 ) . mean quality score by center , adjusted for patient characteristics and clustering effect , is in supplementary fig . when the score was tested as the dependent variable , it emerged that 25% of the variance in the score ( icc = 0.25 ) could be attributed to between center variation ( i.e. , to setting characteristics ) . when adjusting for case - mix ( age , sex , bmi , duration of diabetes , previous cv events ) , variance attributable to center - level characteristics remained elevated ( icc = 0.18 ) . improving health outcomes is the ultimate goal of the health care system and should represent the main aim for any quality measurement program . from the data on more than 5,000 patients with type 2 diabetes mellitus routinely cared for by diabetes clinics and followed up for a median of 28 months , we confirmed that a quality - of - care summary score , based on a restricted number of indicators , is able to predict total cardiovascular events . the trend of increase in the event rates with the progressive reduction of the score is clear for all the selected outcomes , including overall mortality , although statistical significance was not reached . our study substantially reproduces the body of evidence emerged by the qued study ( 14 ) , confirming the validity and applicability of the instrument . in comparison with previous studies ( 14,17 ) , conducted ten years ago in comparable settings , quality of care has improved , as reflected by the lower percentage of patients scoring below 15 and the general shift of the score distribution toward higher values . patients with a particularly high risk of negative outcomes , i.e. , those with a score of < 15 , now represent a small minority ( 6.7% ) . acting to improve the performance in this small subgroup would hardly translate into tangible results at the population level , although individual patients would benefit from any quality improvement . on the other side , a large proportion of patients ( i.e. , 68.2% ) lies in the 1525 score range , associated with a nearly 20% increased risk of major events . a substantially greater benefit could thus be expected by improving the monitoring and treatment of major cardiovascular risk factors in such a large population . the score can help identifying patients whose quality of care is suboptimal and in which aspects of care need to be improved . reducing variation in health care delivery represents a key component of any quality improvement initiative ( 18 ) . in our study , it has been argued that process and intermediate outcomes can be affected not only by medical interventions but also by patient factors ( 19 ) ; in other words , the score might reflect patient variation rather than disparities in the quality of care . we showed that a relevant proportion of total variance was explained by center - level characteristics ( 16 ) , even after adjusting for patient case - mix . to this respect the wide variation in health care delivery strongly suggests that a substantial proportion of cardiovascular events could be avoided by providing higher quality and more homogeneous levels of care . the use of more standardized approaches could lead to sizeable savings in care and outcomes , particularly focusing the attention on the large proportion of patients falling in the intermediate category of the score . the possibility of calculating the quality score from electronic medical records in an easy and quick way makes its use particularly appealing . by allowing its automatic calculation , the score could be used not only to identify patients at risk for poor quality of care but also to monitor the performance of the center across the years . the score can also be used for multicenter , continuous quality improvement initiatives by providing a benchmark to which to compare individual performance . this approach is being adopted in the context of a wide national initiative in italy , involving over 250 diabetes clinics for a total of half a million patients . the score will be calculated at the national , regional , and individual center levels , and the overall performance will be measured against that of the best performers . some of the potential limitations of our study need to be discussed . they could thus represent those clinicians more interested in diabetes care and therefore not reflect the diabetes care delivered by italian physicians . it is thus possible that the differences documented in our study are underestimated and that the true variability in process and outcome measures is even greater . similarly , patients attending diabetes clinics might differ from those primarily cared for by gps ; therefore , they could not be representative of all patients with diabetes . second , the attainment of the desired therapeutic goals could be at least partially dependent on unmeasured patient factors ; therefore , the intermediate outcome measures considered might not fully reflect the care provided . third , the relatively short follow - up did not allow a robust estimate of the impact of the score on individual cardiovascular outcomes . furthermore , an update of the study has been scheduled to evaluate the incidence rate of cv events after a 5-year follow - up . finally , we have developed a score able to predict major cardiovascular events ; a comprehensive quality - of - care measure should obviously also include process and outcome measures related to microvascular complications . in conclusion , our study documented a close relationship between quality of diabetes care and long - term outcomes . our findings support the use of the indicators identified as an important tool to assess the level of care provided within systems of care to populations of patients with diabetes .
objectivethe quasar ( quality assessment score and cardiovascular outcomes in italian diabetes patients ) study aimed to assess whether a quality - of - care summary score predicted the development of cardiovascular ( cv ) events in patients with type 2 diabetes.research design and methodsin 67 diabetes clinics , data on randomly selected patients were extracted from electronic medical records . 
 the score was calculated using process and outcome indicators based on monitoring , targets , and treatment of a1c , blood pressure , ldl cholesterol , and microalbuminuria . 
 the score ranged from 0 to 40.resultsoverall , 5,181 patients were analyzed ; 477 ( 9.2% ) patients developed a cv event after a median follow - up of 28 months . 
 the incidence rate ( per 1,000 person - years ) of cv events was 62.4 in patients with a score of < 15 , 41.0 in those with a score between 20 and 25 and 36.7 in those with a score of > 25.multilevel analysis , adjusted for clustering and case - mix , showed that the risk to develop a new cv event was 84% higher in patients with a score of < 15 ( incidence rate ratio [ irr ] = 1.84 ; 95% confidence interval [ ci ] 1.292.62 ) and 17% higher in those with a score between 15 and 25 ( irr = 1.17 ; 95% ci 0.931.49 ) compared with those with a score of > 25.mean quality score varied across centers from 16.5  7.5 to 29.1  6.3 . when the score was tested as the dependent variable 
 , it emerged that 18% of the variance in the score could be attributed to setting characteristics.conclusionsour study documented a close relationship between quality of diabetes care and long - term outcomes . 
 a simple score can be used to monitor quality of care and compare the performance of different centers / physicians .