Estimating utilities for chronic kidney disease, using SF-36 and SF-12-based measures: challenges in a population of veterans with diabetes

A cost-effectiveness analysis of linagliptin add-on to insulin treatment for patients with type 2 diabetes mellitus and chronic kidney disease in Iran

Purpose

With the high prevalence of chronic kidney disease (CKD) in patients with type 2 diabetes mellitus (T2DM), determining optimal treatment strategies has become a major concern. Linagliptin is aDPP-4 inhibitor that does not require dose adjustment in patients with renal impairment. This study evaluates the cost-effectiveness of adding linagliptin to insulin therapy in patients with T2DM and mild (stage 2) or moderate (stage 3) CKD from a health system perspective in Iran.

Methods

We developed a cost-utility model using a decision tree and ran it separately for T2DM patients with mild or moderate CKD. Clinical outcomes and health-state utility values were extracted from published studies. Direct medical costs were obtained from national tariffs in Iran in 2021. We adopted an annual time horizon and calculated the difference in costs and quality-adjusted life-years (QALYs) to obtain the incremental cost-effectiveness ratios (ICER). To capture parameter uncertainties, one-way sensitivity analyses were also performed.

Results

In T2DM patients with mild CKD, the linagliptin add-on strategy was associated with an additional $23.69 cost and 0.0148 QALYs per patient, resulting in an ICER of 1600.37 USD/QALY. In moderate CKD, the strategy was associated with $22.59 more costs and 0.0191 more QALYs, and the ICER was estimated at 1182.72 USD/QALY. In both populations, the ICER was mainly driven by the impact of HbA1c on utility, cost of linagliptin, and the reduction in insulin usage by adding linagliptin to the treatment.

Conclusion

With a cost-effectiveness threshold of $1550 USD/QALY in Iran, adding linagliptin to insulin is cost-effective in patients with T2DM and moderate CKD. However, for those with mild CKD, it seems that the associated costs outweigh the expected benefits.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40200-023-01243-z.

Economic Modelling of Chronic Kidney Disease: A Systematic Literature Review to Inform Conceptual Model Design

BACKGROUND

Chronic kidney disease (CKD) is a progressive condition that leads to irreversible damage to the kidneys and is associated with an increased incidence of cardiovascular events and mortality. As novel interventions become available, estimates of economic and clinical outcomes are needed to guide payer reimbursement decisions.

OBJECTIVE

The aim of the present study was to systematically review published economic models that simulated long-term outcomes of kidney disease to inform cost-effectiveness evaluations of CKD treatments.

METHODS

The review was conducted across four databases (MEDLINE, Embase, the Cochrane library and EconLit) and health technology assessment agency websites. Relevant information on each model was extracted. Transition and mortality rates were also extracted to assess the choice of model parameterisation on disease progression by simulating patient's time with end-stage renal disease (ESRD) and time to ESRD/death. The incorporation of cardiovascular disease in a population with CKD was qualitatively assessed across identified models.

RESULTS

The search identified 101 models that met the criteria for inclusion. Models were classified into CKD models (n = 13), diabetes models with nephropathy (n = 48), ESRD-only models (n = 33) and cardiovascular models with CKD components (n = 7). Typically, published models utilised frameworks based on either (estimated or measured) glomerular filtration rate (GFR) or albuminuria, in line with clinical guideline recommendations for the diagnosis and monitoring of CKD. Generally, two core structures were identified, either a microsimulation model involving albuminuria or a Markov model utilising CKD stages and a linear GFR decline (although further variations on these model structures were also identified). Analysis of parameter variability in CKD disease progression suggested that mean time to ESRD/death was relatively consistent across model types (CKD models 28.2 years; diabetes models with nephropathy 24.6 years). When evaluating time with ESRD, CKD models predicted extended ESRD survival over diabetes models with nephropathy (mean time with ESRD 8.0 vs. 3.8 years).

DISCUSSION

This review provides an overview of how CKD is typically modelled. While common frameworks were identified, model structure varied, and no single model type was used for the modelling of patients with CKD. In addition, many of the current methods did not explicitly consider patient heterogeneity or underlying disease aetiology, except for diabetes. However, the variability of individual patients' GFR and albuminuria trajectories perhaps provides rationale for a model structure designed around the prediction of individual patients' GFR trajectories. Frameworks of future CKD models should be informed and justified based on clinical rationale and availability of data to ensure validity of model results. In addition, further clinical and observational research is warranted to provide a better understanding of prognostic factors and data sources to improve economic modelling accuracy in CKD.

Population level outcomes and cost-effectiveness of hepatitis C treatment pre- vs postkidney transplantation

Direct-acting antivirals approved for use in patients with end-stage renal disease (ESRD) now exist. HCV-positive (HCV+) ESRD patients have the opportunity to decrease the waiting times for transplantation by accepting HCV-infected kidneys. The optimal timing for HCV treatment (pre- vs posttransplant) among kidney transplant candidates is unknown. Monte Carlo microsimulation of 100 000 candidates was used to examine the cost-effectiveness of HCV treatment pretransplant vs posttransplant by liver fibrosis stage and waiting time over a lifetime time horizon using 2 regimens approved for ESRD patients. Treatment pretransplant yielded higher quality-adjusted life years (QALYs) compared with posttransplant treatment in all subgroups except those with Meta-analysis of Histological Data in Viral Hepatitis stage F0 (pretransplant: 5.7 QALYs vs posttransplant: 5.8 QALYs). However, treatment posttransplant was cost-saving due to decreased dialysis duration with the use of HCV-infected kidneys (pretransplant: $735 700 vs posttransplant: $682 400). Using a willingness-to-pay threshold of $100 000, treatment pretransplant was not cost-effective except for those with Meta-analysis of Histological Data in Viral Hepatitis stage F3 whose fibrosis progression was halted. If HCV+ candidates had access to HCV-infected donors and were transplanted ≥9 months sooner than HCV-negative candidates, treatment pretransplant was no longer cost-effective (incremental cost-effectiveness ratio [ICER]: $107 100). In conclusion, optimal timing of treatment depends on fibrosis stage and access to HCV+ kidneys but generally favors posttransplant HCV eradication.

Substitution of SF-36 by SF-12 Among Hong Kong Chinese Older Adults: Secondary Analysis of Randomized Controlled Trials

PURPOSE

This study aims to examine the appropriateness of substituting the Short-Form 36 (SF-36) by its shortened version (SF-12) in measuring health-related quality of life (HRQoL) in older Chinese population.

METHODS

Secondary analysis of two transitional care management programs, conducted from 2009 to 2012, were analyzed (n = 1188, aged 60-97). Participants were discharged patients with respiratory disease, type 2 diabetes, cardiac disease, and renal disease, and were classified according to number of chronic diseases. SF-36 was administered at baseline and 4-week follow-up.

RESULTS

Both overestimations and underestimations of HRQoL by SF-12 were found. Most domain scores of SF-36 and SF-12 were highly correlated (Spearman correlation (ρ) > 0.85), with the exception of General Health (ρ = 0.64) and Vitality subscales (ρ = 0.82). Multiple linear regression adjusted for demographic characteristics showed that the four out of eight domains of SF-36 and SF-12 were equivalent in measuring the difference across numbers of chronic diseases (all p < 0.05). Paired sample t tests in 989 (83.2 %) who completed the SF-36 survey 4 weeks after baseline showed that SF-12 overestimated the 4-week changes in most of the domains.

CONCLUSIONS

The use of the Chinese version of SF-12v2 for reporting the change over time in quality of life among medical patients after hospital discharge may need to be interpreted with caution. The SF-12 tends to underestimate the difference when compared with the SF-36.

Collection of daily patient reported outcomes is feasible and demonstrates differential patient experience in chronic kidney disease

INTRODUCTION

Patient reported outcomes (PROs) are a critical metric documenting the impact of disease and treatment from the patient's perspective. A variety of generic and disease specific PRO measures (PROMs) are used in chronic kidney disease (CKD) but studies are primarily cross-sectional. None of the available PROMs are designed for frequent iterative application.

METHODS

An online PROM for daily use in dialysis and CKD 4/5 patients was developed. The custom website utilised visual analogue scales to capture 6 PROs (general well being (GWB), pain, sleep, breathing, energy, and appetite). Outcomes of interest were uptake, response rates, intermodality variation, and change in PRO corresponding to predefined events.

FINDINGS

Forty-three patients submitted at least once and 34 submitted beyond 30 days. Median follow-up was 247 days, 64% male, age 62 ± 12 years. In individuals submitting for >30 days, dialysis patients had significantly worse median scores compared to CKD for sleep (47[32-80], 97[76-99], P = 0.003), appetite (66[50-96], 97[88-100], P = 0.008), energy (47[40-89], 84[67-96], P = 0.031), and GWB (63[49-94], 93[71-98], P = 0.026). Patients demonstrated a variety of stable bandwidths of response, deviations from this were associated with specific events e.g., acute admission, vascular procedures, disturbed fluid status, and dialysis start.

DISCUSSION

We successfully introduced an online, patient acceptable, iterative PROM that discriminates symptom burden, cross-sectionally, and longitudinally. Further work will prospectively examine the predictive power of changes in PRO and more rigorously investigate the potential use of these methods to optimise patient care.

Comparison of the preference-based EQ-5D-5L and SF-6D in patients with end-stage renal disease (ESRD)

OBJECTIVES

The objective of this study was to compare the performance of the 5-level EuroQol 5-dimension (EQ-5D-5L) and the Short Form 6-dimension (SF-6D) instruments in assessing patients with end-stage renal disease (ESRD) in Singapore.

METHODS

In a cross-sectional study, ESRD patients attending a tertiary hospital were interviewed using a battery of questionnaires including the EQ-5D-5L, the kidney disease quality of life instrument (KDQOL-36), and questions assessing dialysis history and socio-demographic characteristics. We reviewed patients' medical records for their clinical information. We assessed the construct validity of the EQ-5D-5L and SF-6D index scores and compared their ability to distinguish between patients differing in health status and the magnitude of between-group difference they quantified.

RESULTS

One hundred and fifty ESRD patients on dialysis (mean age, 60.1 years; female, 48.7%) participated in the study. Both EQ-5D-5L and SF-6D demonstrated satisfactory known-groups validity; the EQ-5D-5L was more sensitive to differences in clinical outcomes and the SF-6D was more sensitive to differences in health outcomes measured by KDQOL scales. The intraclass correlation coefficient between the measures was 0.36. The differences in the EQ-5D-5L index score for patients in better and worse health status were greater than those measured by the SF-6D index score.

CONCLUSIONS

Both EQ-5D-5L and SF-6D are valid instruments for assessing ESRD patients. However, the two preference-based measures cannot be used interchangeably and it appears that EQ-5D-5L would lead to more favorable cost-effectiveness results than SF-6D if they are used in economic evaluations of interventions for ESRD.

THE IMPACT OF SOCIOECONOMIC FACTORS ON QUALITY OF LIFE OF PATIENTS WITH CHRONIC KIDNEY DISEASE IN GREECE

BACKGROUND

Quality of Life (QoL) is often poor in people undergoing dialysis and this sometimes contributes to the high rate of morbidity and mortality. The aim of our study is to assess the QoL of patients on haemodialysis in Greece and discuss the socio-demographic factors that affect QoL in this period of financial crisis.

DESIGN/PATIENTS

Patients with CKD not on dialysis, plus those undergoing Haemodialysis (HD) and Peritoneal Dialysis (PD) were invited to complete the SF-36 questionnaire electronically, supervised by a trained nurse. Patients were asked about their marital status, education level and monthly household income. Additionally, patients were requested to comment on their subjective financial difficulties.

RESULTS

A total of 172 patients were enrolled in the study, 39 of them were undergoing PD, 90 on HD and 43 had CKD. Among those with CKD, on HD and PD, 9.3%, 17.8% and 23.1%, respectively, had 'some/a lot' difficulties in copying with financial problems. The physical component summary score was significant lower in HD, while the summary score of the mental component showed no differences between the groups. In multiple linear regression analysis, age and dialysis had significantly negative correlations with physical functioning scores. Those who were divorced or widowed tended to perform worse in physical scores compared with those who were married. Mental scores were affected only by coping with financial difficulties.

CONCLUSIONS

In general terms, people with CKD patients present with a poor QoL. Apart from the burden of the renal disease per se, social and economic factors (divorce, financial difficulties) seem to aggravate their status, especially in this period of financial crisis.