Konstantin Tachkov

Dr. Konstantin Tachkov

orcid

Research Focus & Metrics

Academic Career Length

13Years (2014-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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2 January 2020 in Expert Review of Pharmacoeconomics & Outcomes Research
Verified
Journal Article
Open access
BGBrian Godman
Brian Godman
HMHolly McCabe
Holly McCabe
TLTrudy Leong
Trudy Leong
DMDebjani Mueller
Debjani Mueller
AMAntony P. Martin
Antony P. Martin
Johanna Catharina MeyerJohanna Catharina Meyer
Johanna Catharina Meyer
Introduction: There are positive aspects regarding the prescribing of fixed dose combinations (FDCs) versus prescribing the medicines separately. However, these have to be balanced against concerns including increased costs and their irrationality in some cases. Consequently, there is a need to review their value among lower- and middle-income countries (LMICs) which have the greatest prevalence of both infectious and noninfectious diseases and issues of affordability. Areas covered: Review of potential advantages, disadvantages, cost-effectiveness, and availability of FDCs in high priority disease areas in LMICs and possible initiatives to enhance the prescribing of valued FDCs and limit their use where there are concerns with their value. Expert commentary: FDCs are valued across LMICs. Advantages include potentially improved response rates, reduced adverse reactions, increased adherence rates, and reduced costs. Concerns include increased chances of drug:drug interactions, reduced effectiveness, potential for imprecise diagnoses and higher unjustified prices. Overall certain FDCs including those for malaria, tuberculosis, and hypertension are valued and listed in the country’s essential medicine lists, with initiatives needed to enhance their prescribing where currently low prescribing rates. Proposed initiatives include robust clinical and economic data to address the current paucity of pharmacoeconomic data. Irrational FDCs persists in some countries which are being addressed.

25 November 2019 in Expert Opinion on Pharmacotherapy
Verified
Journal Article
Open access
BGBrian Godman
Brian Godman
CGChristoffel Grobler
Christoffel Grobler
MVMarianne Van-De-Lisle
Marianne Van-De-Lisle
JWJanney Wale
Janney Wale
WBWallace Breno Barbosa
Wallace Breno Barbosa
CBCorrado Barbui
Corrado Barbui
Introduction: Appropriately managing mental disorders is a growing priority across countries in view of the impact on morbidity and mortality. This includes patients with bipolar disorders (BD). Management of BD is a concern as this is a complex disease with often misdiagnosis, which is a major issue in lower and middle-income countries (LMICs) with typically a limited number of trained personnel and resources. This needs to be addressed. Areas covered: Medicines are the cornerstone of managing patients with Bipolar II across countries including LMICs. The choice of medicines, especially antipsychotics, is important in LMICs with high rates of diabetes and HIV. However, care is currently compromised in LMICs by issues such as the stigma, cultural beliefs, a limited number of trained professionals and high patient co-payments. Expert opinion: Encouragingly, some LMICs have introduced guidelines for patients with BD; however, this is very variable. Strategies for the future include addressing the lack of national guidelines for patients with BD, improving resources for mental disorders including personnel, improving medicine availability and patients’ rights, and monitoring prescribing against agreed guidelines. A number of strategies have been identified to improve the treatment of patients with Bipolar II in LMICs, and will be followed up.

18 May 2019 in The European Journal of Health Economics
Verified
Journal Article
Open access
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VBValentin Brodszky
Valentin Brodszky
ZBZsuzsanna Beretzky
Zsuzsanna Beretzky
Petra BajiPetra Baji
Petra Baji
FRFanni Rencz
Fanni Rencz
MPMárta Péntek
Márta Péntek
LGLászló Gulácsi
László Gulácsi
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.

18 July 2018 in Frontiers in Pharmacology
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Journal Article
Open access
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VBVladimira V. Boyadzieva
Vladimira V. Boyadzieva
NSNikolay Stoilov
Nikolay Stoilov
RSRumen M. Stoilov
Rumen M. Stoilov
KTKonstantin Tachkov
Konstantin Tachkov
MKMaria Kamusheva
Maria Kamusheva
Guenka PetrovaGuenka Petrova
Guenka Petrova
Biological medicines are considered as a cornerstone in the therapy of rheumatoid arthritis (RA). They change the course of the disease and improve the quality of life of patients. To this date there has been no study comparing the quality of life of and cost of RA therapy in Bulgaria. This fact is what provoked our interest toward this research. The aim of this study is to analyse the cost and quality of life of patients with RA threated with biological medicines in Bulgaria. This is an observational, real life study of 124 patients treated with biological medicines during 2012–2016 at the University hospital “St. Ivan Riskli” in Sofia, specialized in rheumatology disease therapy. Patients were recruited after their consecutive transfer from non-biological to biological medicines. The yearly pharmacotherapy cost was calculated with tocilizumab (n = 30), cetrolizmab (n = 16), golimumab (n = 22), etanercept (n = 20), adalimumab (n = 20), rituximab (n = 16). Three measurements of the quality of life (QoL) were performed with EQ5D—at the beginning of the therapy, after 6 months and after 1 year of therapy. Both section of EQ5D were used—VAS and EQ5D questionnaire. Cost—effectiveness was calculated for unit of improvement in EQ5D score for a one year period and decision model was built with TreeAgePro software. The observed cost of therapy varied between 12 thousand Euros for tocilizumab to 6 thousand Euros for rituximab. All biological medicines let to substantial increase in the quality of life of the patients. Patients on tocilizumab increased their QoL from 0.43 to 0.63 after 1 year; on cetrolizumab from 0.32 to 0.56; on golimumab from 0.41 to 0.67; on etanercept from 0.45 to 0.62; on adalimumab from 0.43 to 0.57; on rhituximab from 0.46 to 0.66. The cost-effectiveness estimates of different biological therapies also varied between 66 to 30 thousand Euros for unit of improvement in the EQ5D during one the course of the year. Therapy with biological medicines improves statistically significant the quality of life of patients, measured through VAS and EQ5D scales. Despite the improvement in the quality of life all biological medicines appears not to be note cost-effective due to their high incremental cost-effectiveness ration (ICER). Rituximab's incremental ratio has (ICER) falls closer to the three times gross domestic product per capita threshold and should be considered as preferred alternatives for RA therapy. In general we can conclude that the treatment of rheumatoid arthritis with biologicals improves quality of life significantly. Only rituximab was cost-effective.

1 January 2021 in BioMed Research International
Verified
Journal Article
Open access
PDF file
BGBrian Godman
Brian Godman
MWMagdalene Wladysiuk
Magdalene Wladysiuk
SMStuart McTaggart
Stuart McTaggart
Amanj KurdiAmanj Kurdi
Amanj Kurdi
EAEleonora Allocati
Eleonora Allocati
BWBjorn Wettermark
Bjorn Wettermark
Background. Diabetes mellitus rates and associated costs continue to rise across Europe enhancing health authority focus on its management. The risk of complications is enhanced by poor glycaemic control, with long‐acting insulin analogues developed to reduce hypoglycaemia and improve patient convenience. There are concerns though with their considerably higher costs, but moderated by reductions in complications and associated costs. Biosimilars can help further reduce costs. However, to date, price reductions for biosimilar insulin glargine appear limited. In addition, the originator company has switched promotional efforts to more concentrated patented formulations to reduce the impact of biosimilars. There are also concerns with different devices between the manufacturers. As a result, there is a need to assess current utilisation rates for insulins, especially long‐acting insulin analogues and biosimilars, and the rationale for patterns seen, among multiple European countries to provide future direction. Methodology. Health authority databases are examined to assess utilisation and expenditure patterns for insulins, including biosimilar insulin glargine. Explanations for patterns seen were provided by senior‐level personnel. Results. Typically increasing use of long‐acting insulin analogues across Europe including both Western and Central and Eastern European countries reflects perceived patient benefits despite higher prices. However, activities by the originator company to switch patients to more concentrated insulin glargine coupled with lowering prices towards biosimilars have limited biosimilar uptake, with biosimilars not currently launched in a minority of European countries. A number of activities were identified to address this. Enhancing the attractiveness of the biosimilar insulin market is essential to encourage other biosimilar manufacturers to enter the market as more long‐acting insulin analogues lose their patents to benefit all key stakeholder groups. Conclusions. There are concerns with the availability and use of insulin glargine biosimilars among European countries despite lower costs. This can be addressed.

2 June 2017 in Biotechnology & Biotechnological Equipment
Verified
Journal Article
Open access
KTKonstantin Tachkov
Konstantin Tachkov
MKMaria Kamusheva
Maria Kamusheva
VPVentsislava Pencheva
Ventsislava Pencheva
KMKonstantin Mitov
Konstantin Mitov
The aim of this study was to calculate the economic and social burden of chronic obstructive pulmonary disease (COPD) in Bulgaria generated from the loss of productivity due to absence from work (absenteeism), due to premature retirement, due to reduced productivity (presenteeism), and the disability adjusted life years (DALY). An observational study among 426 Bulgarian COPD patients was conducted for the period 2014–2015. Human capital approach was used to calculate the productivity losses and the DALY methodology of the World Health Organization was applied. The patients with moderate (50%) and severe (48%) disease were absent from work more frequently than those with mild COPD (2%) and generated productivity losses of 521.45€ per patient per year. The average indirect costs per patient for the remaining working ages due to premature retirement account for 25,000€ (6250 per patient on average), while those due to presenteeism, for about 3750.64€ per year. Accordingly, the DALYs in the group of patients with mild severity were lowest due to the low disutility index and number of patients in this sample group. On average, a patient with mild COPD spends 0.62 years of his life in disability due to the disease, while those with moderate and severe disease spend 6.00 and 9.00 years, respectively. This amounted to the following indirect costs experienced by patients: 3596.52€; 34,204.01€; 51,332.20€, respectively. We demonstrated a significant indirect financial and societal burden of COPD in Bulgaria, which is in correlation with the severity of the disease.