Cost-of-illness analysis and regression modeling in cystic fibrosis: a retrospective prevalence-based study

Measuring the burden of cystic fibrosis: A scoping review

BACKGROUND

Cystic fibrosis (CF) contributes a significant economic burden on individuals, healthcare systems, and society. Understanding the economic impact of CF is crucial for planning resource allocation.

METHODS

We conducted a scoping review of literature published between 1990 and 2022 that reported the cost of illness, and/or economic burden of CF. Costs were adjusted for inflation and reported as United States dollars.

RESULTS

A total of 39 studies were included. Direct healthcare costs (e.g., medications, inpatient and outpatient care) were the most frequently reported. Most studies estimated the cost of CF using a prevalence-based (n = 18, 46.2 %), bottom-up approach (n = 23, 59 %). Direct non-healthcare costs and indirect costs were seldom included. The most frequently reported direct cost components were medications (n = 34, 87.2 %), inpatient care (n = 33, 84.6 %), and outpatient care (n = 31, 79.5 %). Twenty-eight percent (n = 11) of studies reported the burden of CF from all three perspectives (healthcare system (payer), individual, and society). Indirect costs of CF were reported in approximately 20 % of studies (n = 8). The reported total cost of CF varied widely, ranging from $451 to $160,000 per person per year (2022 US$). The total cost depended on the number of domains and perspectives included in each study.

CONCLUSIONS

Most studies only reported costs to the healthcare system (i.e., hospitalizations and healthcare encounters) which likely underestimates the total costs of CF. The wide range of costs reported highlights the importance of standardizing perspectives, domains and costs when estimating the economic burden of CF.

Factors associated with frequent high-cost individuals with cystic fibrosis and their healthcare utilization and cost patterns

Cystic fibrosis (CF) is a progressive multi-organ disease with significant morbidity placing extensive demands on the healthcare system. Little is known about those individuals with CF who continually incur high costs over multiple years. Understanding their characteristics may help inform opportunities to improve management and care, and potentially reduce costs. The purpose of this study was to identify and understand the clinical and demographic attributes of frequent high-costing CF individuals and characterize their healthcare utilization and costs over time. A longitudinal study of retrospective data was completed in British Columbia, Canada by linking the Canadian CF Registry with provincial healthcare administrative databases for the period between 2009 and 2017. Multivariable Cox regression models were employed to identify baseline factors associated with becoming a frequent high-cost CF user (vs. not a frequent high-cost CF user) in the follow-up period. We found that severe lung impairment (Hazard Ratio [HR]: 3.71, 95% confidence interval [CI], 1.49-9.21), lung transplantation (HR: 4.23, 95% CI, 1.68-10.69), liver cirrhosis with portal hypertension (HR: 10.96, 95% CI: 3.85-31.20) and female sex (HR: 1.97, 95% CI: 1.13-3.44) were associated with becoming a frequent high-cost CF user. Fifty-nine (17% of cohort) frequent high-cost CF users accounted for more than one-third of the overall total healthcare costs, largely due to inpatient hospitalization and outpatient medication costs.

Cost-of-illness studies in rare diseases: a scoping review

Objective

The aim of this scoping review was to overview the cost-of-illness studies conducted in rare diseases.

Methods

We searched papers published in English in PubMed from January 2007 to December 2018. We selected cost-of-illness studies on rare diseases defined as those with prevalence lower than 5 per 10,000 cases. Studies were selected by one researcher and verified by a second researcher. Methodological characteristics were extracted to develop a narrative synthesis.

Results

We included 63 cost-of-illness studies on 42 rare diseases conducted in 25 countries, and 9 systematic reviews. Most studies (94%) adopted a prevalence-based estimation, where the predominant design was cross-sectional with a bottom-up approach. Only four studies adopted an incidence-based estimation. Most studies used questionnaires to patients or caregivers to collect resource utilisation data (67%) although an important number of studies used databases or registries as a source of data (48%). Costs of lost productivity, non-medical costs and informal care costs were included in 68%, 60% and 43% of studies, respectively.

Conclusion

This review found a paucity of cost-of-illness studies in rare diseases. However, the analysis shows that the cost-of-illness studies of rare diseases are feasible, although the main issue is the lack of primary and/or aggregated data that often prevents a reliable estimation of the economic burden.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13023-021-01815-3.

Cost-of-illness studies in rare diseases: a scoping review

OBJECTIVE

The aim of this scoping review was to overview the cost-of-illness studies conducted in rare diseases.

METHODS

We searched papers published in English in PubMed from January 2007 to December 2018. We selected cost-of-illness studies on rare diseases defined as those with prevalence lower than 5 per 10,000 cases. Studies were selected by one researcher and verified by a second researcher. Methodological characteristics were extracted to develop a narrative synthesis.

RESULTS

We included 63 cost-of-illness studies on 42 rare diseases conducted in 25 countries, and 9 systematic reviews. Most studies (94%) adopted a prevalence-based estimation, where the predominant design was cross-sectional with a bottom-up approach. Only four studies adopted an incidence-based estimation. Most studies used questionnaires to patients or caregivers to collect resource utilisation data (67%) although an important number of studies used databases or registries as a source of data (48%). Costs of lost productivity, non-medical costs and informal care costs were included in 68%, 60% and 43% of studies, respectively.

CONCLUSION

This review found a paucity of cost-of-illness studies in rare diseases. However, the analysis shows that the cost-of-illness studies of rare diseases are feasible, although the main issue is the lack of primary and/or aggregated data that often prevents a reliable estimation of the economic burden.

The Factors Associated With Direct Medical Costs in Patients With Gastric Cancer: Quantile Regression Approach Compared With Gamma Regression

OBJECTIVES

Evaluating the costs of illness can provide evidence to improve performance at all levels of health organizations. This study aimed to identify the relationship between the costs of diagnosing and treating patients with gastric cancer and their explanatory variables, using quantile and gamma regressions and comparing the results of the two models.

METHODS

This was a cross-sectional and descriptive-analytic study carried out in 2016. In total, 449 patients with gastric cancer were selected at a hospital affiliated with Mashhad University of Medical Sciences. Direct costs and other variables were collected from medical documents. Data were analyzed using the STATA 12 software, using quantile and gamma regression analysis, and the results were compared.

RESULTS

The highest average cost per patient was related to hospitalization costs in both metastatic (20 911 034 Iranian Rials) and nonmetastatic patients (20 738 062 Iranian Rials). The lowest average cost was related to biopsy services in nonmetastatic patients. The results of the study also showed that quantile regression is an appropriate substitute for gamma regression and, in some cases, can provide more information for the analysis of disease costs. Based on the results of the quantile regression, being a male and having a shorter stay had a positive effect on cost and the age of the patient had a significantly negative effect.

CONCLUSIONS

Examining the cost of a common illness, such as gastric cancer, is an important economic tool for policy makers and decision makers. It provides evidence-based decision making about resource allocation that they can use for future planning and cost control.

Cost-of-illness studies in nine Central and Eastern European countries

BACKGROUND

To date, a multi-country review evaluating the cost-of-illness (COI) studies from the Central and Eastern European (CEE) region has not yet been published. Our main objective was to provide a general description about published COI studies from CEE.

METHODS

A systematic search was performed between 1 January 2006 and 1 June 2017 in Medline, EMBASE, The Cochrane Library, CINAHL, and Web of Science to identify all relevant COI studies from nine CEE countries. COI studies reporting costs without any restrictions by age, co-morbidities, or treatment were included. Methodology, publication standards, and cost results were analysed.

RESULTS

We identified 58 studies providing 83 country-specific COI results: Austria (n = 9), Bulgaria (n = 16), Croatia (n = 3), the Czech Republic (n = 10), Hungary (n = 24), Poland (n = 11), Romania (n = 3), Slovakia (n = 3), and Slovenia (n = 4). Endocrine, nutritional, and metabolic diseases (18%), neoplasms (12%), infections (11%), and neurological disorders (11%) were the most frequently studied clinical areas, and multiple sclerosis was the most commonly studied disease. Overall, 57 (98%) of the studies explicitly stated the source of resource use data, 45 (78%) the study perspective, 34 (64%) the costing method, and 24 (58%) reported at least one unit costs. Regardless of methodological differences, a positive relationship was observed between costs of diseases and countries' per capita GDP.

CONCLUSIONS

Cost-of-illness studies varied considerably in terms of methodology, publication practice, and clinical areas. Due to these heterogeneities, transferability of the COI results is limited across Central and Eastern European countries.

Mapping Quality of Life (EQ-5D) from DAPsA, Clinical DAPsA and HAQ in Psoriatic Arthritis

BACKGROUND

Clinical trials and observational studies lacking measures of health-related quality of life (QoL) are often inapplicable when conducting cost-effectiveness analyses using quality-adjusted life-years (QALYs). The only solution is to map QoL ex post from additionally collected clinical outcomes and generic QoL instruments. Nonetheless, mapping studies are absent in psoriatic arthritis (PsA).

METHODS

In this 2-year, prospective, multicentre, non-interventional study of PsA patients, EQ-5D and key clinical parameters such as Disease Activity in PsA (DAPsA), clinical DAPsA (cDAPsA; DAPsA without C-reactive protein [CRP]), and Health Assessment Questionnaire disability index (HAQ) were collected. We employed a linear mixed-effect regression model (ME) of the longitudinal dataset to explore the best predictors of QoL.

RESULTS

A total of 228 patients were followed over 873 appointments/observations. DAPsA, cDAPsA and HAQ were stable and highly significant predictors of EQ-5D utilities in both cross-sectional and longitudinal analyses. The best prediction was provided using a linear ME with HAQ and cDAPsA or DAPsA. A HAQ increase of 1 point represented a decrease in EQ-5D by -0.204 or -0.203 (p < 0.0001); a one-point increase in cDAPsA or DAPsA dropped EQ-5D equally by -0.005 (p < 0.0001). The ME revealed steeper and more accurate association compared with cross-sectional regressions or non-linear models/transformations.

CONCLUSIONS

This is the first mapping study conducted in PsA and we hope that our study will encourage further mapping studies in PsA. The results showed that in cases where CRP is absent, cDAPsA provides similar results to DAPsA in predicting QoL.

Dietary patterns, cost and compliance with low-protein diet of phenylketonuria and other inherited metabolic diseases

BACKGROUND/OBJECTIVES

Phenylketonuria (PKU) and several other inherited metabolic diseases (IMD) require a lifelong low-protein diet (LPD), otherwise they lead to many health complications. LPDs, however, carry a significant economic burden for patients and their families. The objective of this study was to explore the costs of low-protein foods (LPFs) necessary for LPD as well as dietary patterns and compliance towards an LPD.

SUBJECTS/METHODS

A detailed questionnaire was created in cooperation with National Association of PKU and other IMD (NSPKU), and consequently sent to all NSPKU members treated with an LPD (n=303). A total of 184 respondents from the Czech Republic were included in the study (174 had PKU, 10 had other IMD).

RESULTS

The average daily consumption of LPF was equal to 411.7 g (PKU) and 345.6 g (other IMD), which corresponds to energy value of 5558 kJ and 4438 kJ, respectively, per patient per day. Patients mostly consumed low-protein flour (≈30% of energy intake), pasta (≈18%), basic pastry (≈15%) and sweets (≈10%). The average monthly costs of LPDs were equal to [euro ]130 (PKU) and [euro ]129 (other IMD) per patient per month. The compliance with LPD was decreasing with increasing age (P<0.0001).

CONCLUSIONS

This is the largest study examining costs and dietary patterns of LPDs in patients with PKU and the first study of this kind in other IMD patients requiring an LPD. The study clearly showed that an LPD carries a very high economic burden for families, which may lead to less LPD compliance and potential severe health consequences.