Risk adjustment and outcome research. Part I

Comparing Cardiovascular Outcomes and Costs of Perindopril-, Enalapril- or Losartan-Based Antihypertensive Regimens in South Africa: Real-World Medical Claims Database Analysis

INTRODUCTION

Differences in class or molecule-specific effects between renin-angiotensin-aldosterone system (RAAS) inhibitors have not been conclusively demonstrated. This study used South African data to assess clinical and cost outcomes of antihypertensive therapy with the three most common RAAS inhibitors: perindopril, losartan and enalapril.

METHODS

Using a large, South African private health insurance claims database, we identified patients with a hypertension diagnosis in January 2015 receiving standard doses of perindopril, enalapril or losartan, alone or in combination with other agents. From claims over the subsequent 5 years, we calculated the risk-adjusted rate of the composite primary outcome of myocardial infarction, ischaemic heart disease, heart failure or stroke; rate of all-cause mortality; and costs per life per month (PLPM), with adjustments based on demographic characteristics, healthcare plan and comorbidity.

RESULTS

Overall, 32,857 individuals received perindopril, 16,693 losartan and 13,939 enalapril. Perindopril-based regimens were associated with a significantly lower primary outcome rate (205 per 1000 patients over 5 years) versus losartan (221; P < 0.0001) or enalapril (223; P < 0.0001). The risk-adjusted all-cause mortality rate was lower with perindopril than enalapril (100 vs. 139 deaths per 1000 patients over 5 years; P = 0.007), but not losartan (100 vs. 94; P = 0.650). Mean (95% confidence interval) overall risk-adjusted cost PLPM was Rands (ZAR) 1342 (87-8973) for perindopril, ZAR 1466 (104-9365) for losartan (P = 0.0044) and ZAR 1540 (77-10,546) for enalapril (P = 0.0003).

CONCLUSION

In South African individuals with private health insurance, a perindopril-based antihypertensive regimen provided better clinical and cost outcomes compared with other regimens.

The National Outcomes Evaluation Programme in Italy: The Impact of Publication of Health Indicators

In Italy the National Outcomes Evaluation Programme, (P.N.E.) is the most comprehensive comparative evaluation of healthcare outcomes at the national level. The aim of this report is to describe the P.N.E. and some of the most relevant results achieved. The P.N.E. analysed 184 indicators on quality of care in 2015-2020 period. The data sources are the Italian Health Information Systems. The indicators reported were: proportion of surgery within 2 days after hip fracture in the elderly (HF), 30-day mortality after hospital admission for acute myocardial infarction (AMI), proportion of reoperations within 90 days of breast-conserving surgery and proportion of primary caesarean deliveries. Risk adjustment methods were used to take into account patients' characteristics. From 2010 to 2020 the proportion of interventions within 2 days after HF increased from 31.3% to 64.6%, the AMI 30-day mortality decreased from 10.4% to 8.3%, the proportion of reinterventions within 90 days of breast-conserving surgery decreased from 12.0% to 5.9% and the proportion of primary caesarean deliveries decreased from 28.4% to 22.7%. Results by area of residence showed heterogeneity of healthcare quality. We observed a general improvement in different clinical areas not always associated with a reduction of heterogeneity among areas of residence.

Thirty-day complications after laparoscopic or open cholecystectomy: a population-based cohort study in Italy

OBJECTIVE

The objective of the study is to evaluate short-term complications after laparoscopic (LC) or open cholecystectomy (OC) in patients with gallstones by using linked hospital discharge data.

DESIGN

Population-based cohort study.

SETTING

Data were obtained from the Regional Hospital Discharge Registry Lazio Region in Central Italy (around 5 million inhabitants) in 2007-2008.

PARTICIPANTS

All patients admitted to hospitals of Lazio with symptomatic gallstones (International Classification of disease, 9th Revision, Clinical Modification (ICD-9-CM)=574) who underwent LC (ICD-9-CM 51.23) or OC (ICD-9-CM 51.22).

OUTCOME MEASURES

(1)'30-day surgical-related complications' defined as any complication of the biliary tract (including postoperative infection, haemorrhage or haematoma or seroma complicating a procedure, persistent postoperative fistula, perforation of bile duct and disruption of wound). (2) '30-day systemic complications' defined as any complications of other organs (including sepsis, infections from other organs, major cardiovascular events and selected adverse events).

RESULTS

13 651 patients were included; 86.1% had LC, 13.9% OC. 2.0% experienced surgical-related complications (SRC), 2.1% systemic complications (SC). The OR of complications after LC versus OC was 0.60 (p<0.001) for SRC and 0.52 (p<0.001) for SC. In relation to SRC, the advantage of LC was consistent across age categories, severity of gallstones and previous upper abdominal surgery, whereas there was no advantage among people with emergency admission (OR=0.94, p=0.764). For SC, no significant advantage of LC was seen among very old people (OR=0.99, p=0.975) and among those with previous upper abdominal surgery (OR=0.86, p=0.905).

CONCLUSIONS

This large observational study confirms that LC is more effective than OC with respect to 30-day complications. Population-based linkage of administrative datasets can enlarge evidence of treatment benefits in clinical practice.

Risk adjustment models for interhospital comparison of CS rates using Robson's ten group classification system and other socio-demographic and clinical variables

Background

Caesarean section (CS) rate is a quality of health care indicator frequently used at national and international level. The aim of this study was to assess whether adjustment for Robson’s Ten Group Classification System (TGCS), and clinical and socio-demographic variables of the mother and the fetus is necessary for inter-hospital comparisons of CS rates.

Methods

The study population includes 64,423 deliveries in Emilia-Romagna between January 1, 2003 and December 31, 2004, classified according to theTGCS. Poisson regression was used to estimate crude and adjusted hospital relative risks of CS compared to a reference category. Analyses were carried out in the overall population and separately according to the Robson groups (groups I, II, III, IV and V–X combined). Adjusted relative risks (RR) of CS were estimated using two risk-adjustment models; the first (M1) including the TGCS group as the only adjustment factor; the second (M2) including in addition demographic and clinical confounders identified using a stepwise selection procedure. Percentage variations between crude and adjusted RRs by hospital were calculated to evaluate the confounding effect of covariates.

Results

The percentage variations from crude to adjusted RR proved to be similar in M1 and M2 model. However, stratified analyses by Robson’s classification groups showed that residual confounding for clinical and demographic variables was present in groups I (nulliparous, single, cephalic, ≥37 weeks, spontaneous labour) and III (multiparous, excluding previous CS, single, cephalic, ≥37 weeks, spontaneous labour) and IV (multiparous, excluding previous CS, single, cephalic, ≥37 weeks, induced or CS before labour) and to a minor extent in groups II (nulliparous, single, cephalic, ≥37 weeks, induced or CS before labour) and IV (multiparous, excluding previous CS, single, cephalic, ≥37 weeks, induced or CS before labour).

Conclusions

The TGCS classification is useful for inter-hospital comparison of CS section rates, but residual confounding is present in the TGCS strata.

P.Re.Val.E.: outcome research program for the evaluation of health care quality in Lazio, Italy

BACKGROUND

P.Re.Val.E. is the most comprehensive comparative evaluation program of healthcare outcomes in Lazio, an Italian region, and the first Italian study to make health provider performance data available to the public. The aim of this study is to describe the P.Re.Val.E. and the impact of releasing performance data to the public.

METHODS

P.Re.Val.E. included 54 outcome/process indicators encompassing many different clinical areas. Crude and adjusted rates were estimated for the 2006-2009 period. Multivariate regression models and direct standardization procedures were used to control for potential confounding due to individual characteristics. Variable life-adjusted display charts were developed, and 2008-2009 results were compared with those from 2006-2007.

RESULTS

Results of 54 outcome indicators were published online at http://www.epidemiologia.lazio.it/prevale10/index.php. Public disclosure of the indicators' results caused mixed reactions but finally promoted discussion and refinement of some indicators. Based on the P.Re.Val.E. experience, the Italian National Agency for Regional Health Services has launched a National Outcome Program aimed at systematically comparing outcomes in hospitals and local health units in Italy.

CONCLUSIONS

P.Re.Val.E. highlighted aspects of patient care that merit further investigation and monitoring to improve healthcare services and equity.

Role of gender and age on early mortality after coronary artery bypass graft in different hospitals: data from a national administrative database

The aim of this study is to evaluate the effect of gender and age on outcome following coronary surgery in several hospitals enrolled in a national quality assessment program. Patients undergoing isolated coronary artery bypass graft (CABG) during 2003-2005 in Italy were included in the study (n=74,577). The outcome measure was 30-day in-hospital mortality. Comorbidities recorded during previous and current hospitalizations were used to define patients' health status and to build the adjustment model. The interaction term (gender*hospital) was introduced into the model to test the effect modification of gender; if present, gender specific models were analyzed to test the effect modification of age. A significant effect modification by gender was found in 39 hospitals; the adjusted odds ratios (AdjORs) showed significant increased risk for females (AdjORs ranging from 3.7 to 21.6). In three of these hospitals a significant increased risk was found for older age (AdjORs for elderly patients ranging from 8.1 to 14.6). Two hospitals showed a significant excess risk for patients ≥75 years (AdjORs=6.6 and 13.8). The technical aspects of surgery could account for the excess risk found in female patients; differences in the entire care process (intraoperative and postoperative management) could explain the variations in outcome among elderly patients.

Risk-adjustment model in health outcomes evaluation: a contribution to strengthen assessment towards quality improvement in interventional cardiology

OBJECTIVE

The aim of this study was to develop a risk adjustment model for major adverse cardiac and cerebrovascular events following percutaneous coronary intervention (PCI), using data from a national registry, and to highlight the use of the risk adjustment when we evaluate the quality of care in interventional cardiology.

DESIGN

The

STUDY DESIGN

was based on a Coorte study. Bivariate and multivariate logistic regression models were used to identify independent risk factors for these major adverse events.

SETTING

A total of 19 hospitals from the Portuguese National Registry of Interventional Cardiology.

PARTICIPANTS

Data from 10.641 consecutives procedures collected between June 30, 2003 and June 30, 2006.

INTERVENTION

Build a risk adjustment model for these major adverse events, following percutaneous coronary intervention.

MAIN OUTCOME MEASURE

Factors that were associated with major adverse cardiac and cerebrovascular events following percutaneous coronary intervention.

RESULTS

The rate of in-hospital major adverse cardiac and cerebrovascular events was 1.9%. Factors associated with major adverse cardiac and cerebrovascular events included, among others: age >80 years (adjusted odds ratio = 3.91); female gender (1.72); and cardiogenic shock (6.05). Overall, a good discrimination was achieved with receiver operating characteristics curve = 0.84 and Hosmer-Lemeshow goodness of fit statistic across groups of risk was not significant (P = 0.18) indicating little departure from a perfect fit.

CONCLUSIONS

These findings will represent an important contribution to quality and safety improvement and should help driving new research and innovative approaches to different subgroups of patients who have higher chances of having an adverse event or poorer outcomes following this intervention.