Economic Burden of Parkinson's Disease: A Multinational, Real-World, Cost-of-Illness Study

BACKGROUND

Parkinson's disease is now one of the fastest-growing neurodegenerative disorders in the developed world, with an increasing prevalence and associated socioeconomic costs. Progression of the disease leads to a gradual deterioration in patients' quality of life, despite optimal treatment, and both medical and societal needs increase, often with the assistance of paid and/or unpaid caregivers.

OBJECTIVE

We aimed to quantify the incremental economic burden of Parkinson's disease by disease severity in a real-world setting across differing geographic regions.

METHODS

Demographics, clinical characteristics, health status, patient quality of life, caregiver burden, and healthcare resource utilization data were drawn from the Adelphi Parkinson's Disease Specific Program™, conducted in the USA, five European countries, and Japan.

RESULTS

A total of 563 neurologists provided data for 5299 individuals with Parkinson's disease; 61% were male, with a mean age of 64 years. Approximately 15% of individuals were deemed to have advanced disease, with significantly more comorbidities, and a poorer quality of life, than those with non-advanced disease. Overall, the mean annual healthcare resource utilization increased significantly with advancing disease, and resulted in a three-fold difference in the USA and Europe. The main drivers behind the high economic burden included hospitalizations, prescription medications, and indirect costs.

CONCLUSIONS

People with Parkinson's disease, and their caregivers, incur a higher economic burden as their disease progresses. Future interventions that can control symptoms or slow disease progression could reduce the burden on people with Parkinson's disease and their caregivers, whilst also substantially impacting societal costs.

Impact of advanced Parkinson's disease on caregivers: an international real-world study

BACKGROUND

Caring for a partner or family member with Parkinson's disease (PD) negatively affects the caregiver's own physical and emotional well-being, especially those caring for people with advanced PD (APD). This study was designed to examine the impact of APD on caregiver perceived burden, quality of life (QoL), and health status.

METHODS

Dyads of people with PD and their primary caregivers were identified from the Adelphi Parkinson's Disease Specific Program (DSP™) using real-world data from the United States, Japan and five European countries. Questionnaires were used to capture measures of clinical burden (people with PD) and caregiver burden (caregivers).

RESULTS

Data from 721 patient-caregiver dyads in seven countries were captured. Caregivers had a mean age 62.6 years, 71.6% were female, and 70.4% were a spouse. Caregivers for people with APD had a greater perceived burden, were more likely to take medication and had lower caregiver treatment satisfaction than those caring for people with early or intermediate PD; similar findings were observed for caregivers of people with intermediate versus early PD. Caregivers for people with intermediate PD were also less likely to be employed than those with early PD (25.3% vs 42.4%) and spent more time caring (6.6 vs 3.2 h/day).

CONCLUSIONS

This real-world study demonstrates that caregivers of people with APD experience a greater burden than those caring for people with early PD. This highlights the importance of including caregiver-centric measures in future studies, and emphasizes the need for implementing treatments that reduce caregiver burden in APD.

TRIAL REGISTRATION

N/A.

Does the 5-2-1 criteria identify patients with advanced Parkinson's disease? Real-world screening accuracy and burden of 5-2-1-positive patients in 7 countries

BACKGROUND

The burden of Parkinson's disease (PD) worsens with disease progression. However, the lack of objective and uniform disease classification challenges our understanding of the incremental burden in patients with advanced Parkinson's disease (APD) and suboptimal medication control. The 5-2-1 criteria was proposed by clinical consensus to identify patients with advancing PD. Our objective was to evaluate the screening accuracy and incremental clinical burden, healthcare resource utilization (HCRU), and humanistic burden in PD patients meeting the 5-2-1 screening criteria.

METHODS

Data were drawn from the Adelphi Parkinson's Disease Specific Program (DSP™), a multi-country point-in-time survey (2017-2020). People with PD who were naive to device-aided therapy and on oral PD therapy were included. Patients meeting the 5-2-1 screening criteria had one or more of the three clinical indicators of APD: (i) ≥5 doses of oral levodopa/day, OR (ii) "off" symptoms for ≥2 h of waking day, OR (iii) ≥1 h of troublesome dyskinesia. Clinician assessment of PD stage was used as the reference in this study. Clinical screening accuracy of the 5-2-1 criteria was assessed using area under the curve and multivariable logistic regression models. Incremental clinical, HCRU, and humanistic burden were assessed by known-group comparisons between 5 and 2-1-positive and negative patients.

RESULTS

From the analytic sample (n = 4714), 33% of patients met the 5-2-1 screening criteria. Among physician-classified APD patients, 78.6% were 5-2-1 positive. Concordance between clinician judgment and 5-2-1 screening criteria was > 75%. 5-2-1-positive patients were nearly 7-times more likely to be classified as APD by physician judgment. Compared with the 5-2-1-negative group, 5-2-1-positive patients had significantly higher clinical, HCRU, and humanistic burden across all measures. In particular, 5-2-1-positive patients had 3.8-times more falls, 3.6-times higher annual hospitalization rate, and 3.4-times greater dissatisfaction with PD treatment. 5-2-1-positive patients also had significantly lower quality of life and worse caregiver burden.

CONCLUSIONS

5-2-1 criteria demonstrated potential as a screening tool for identifying people with APD with considerable clinical, humanistic, and HCRU burden. The 5-2-1 screening criteria is an objective and reliable tool that may aid the timely identification and treatment optimization of patients inadequately controlled on oral PD medications.

Psychometric Properties of Clinical Indicators for Identification and Management of Advanced Parkinson's Disease: Real-World Evidence From G7 Countries

Introduction

Standardized and validated criteria to define advanced Parkinson’s disease (PD) or identify patient eligibility for device-aided therapy are needed. This study assessed the psychometric properties of clinical indicators of advanced PD and eligibility for device-aided therapy in a large population.

Methods

This retrospective analysis of the Adelphi Parkinson’s Disease Specific Programme collected data from device-aided therapy-naïve people with PD in G7 countries. We assessed the presence of 15 clinical indicators of advancing PD and seven indicators of eligibility for device-aided therapy in patients classified with advanced PD or as eligible for device-aided therapy by the treating physician. Accuracy was assessed using area under the curve (AUC) and multivariable logistic regression models. Construct validity was examined via known-group comparisons of disease severity and burden among patients with and without each clinical indicator.

Results

Of 4714 PD patients, 14.9% were classified with advanced PD and 17.5% as eligible for device-aided therapy by physician judgment. The presence of each clinical indicator was 1.9- to 7.3-fold more likely in patients classified with advanced PD. Similarly, the presence of device-aided therapy eligibility indicators was 1.8- to 5.5-fold more likely in patients considered eligible for device-aided therapy. All indicators demonstrated high clinical screening accuracy for identifying advanced PD (AUC range 0.84–0.89) and patients eligible for device-aided therapy (AUC range 0.73–0.80). The Unified Parkinson’s Disease Rating Scale (UPDRS) score, cognitive function, quality of life, and caregiver burden were significantly worse in indicator-positive patients.

Conclusion

Specific clinical indicators of advanced PD and eligibility for device-aided therapy demonstrated excellent psychometric properties in a large sample, and thus may provide an objective and reliable approach for patient identification and treatment optimization.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40120-021-00313-9.

Advanced Parkinson’s disease (PD) refers to the stage of disease when motor complications are difficult to manage with standard therapy. Patients reaching this stage of the disease may benefit from a treatment change from pills to the so-called device-aided therapies. However, there is currently no unanimous definition of advanced PD, which makes it challenging to identify suitable candidates for device-aided therapies. There is urgent need to define specific features (or ‘clinical indicators’) to support healthcare professionals and patients in the identification of advanced PD as well as to define suitability for device-aided therapy. This study aimed to assess the accuracy of 15 clinical indicators and seven device-aided therapy eligibility criteria using information from a large database of 4714 patients in G7 countries. Physicians classified 14.9% of patients as having advanced PD and 17.5% were judged to be eligible for device-aided therapy. Each clinical indicator or device-aided therapy eligibility indicator was detected more frequently in patients classified as having advanced PD and in patients considered eligible for device-aided therapy, respectively. All indicators had high accuracy for identifying advanced PD and device-aided therapy-eligibility. These previously identified clinical indicators of advanced PD and device-aided therapy eligibility may provide an objective and reliable approach for patient screening and treatment optimization.

Distribution of the carbohydrate polymer in 14C-labelled iron-poly (sorbitol-gluconic acid) complex after intramuscular administration in normal and anaemic rats

The carbohydrate polymer in an iron-poly (sorbitol-gluconic acid) complex was prepared by using uniformly labelled 14C-sorbitol or 14C-gluconic acid. The distribution of these complexes 7, 14 and 28 days after administration has been followed in non-anaemic and anaemic rats. Most of the 14C from the labelled complexes was found in the expired CO2, faeces and urine. Twenty-eight days after injection of 14C-labelled Ferastral, less than 13% of the given dose of either 14C-sorbitol or 14C-gluconic acid labelled preparation could be found in the body. There was no specific accumulation of 14C in any organ except in the bones, where 3% of the given dose could be seen 28 days after 14C-gluconic acid labelled Ferastral to both non-anaemic and anaemic animals.

Studies on the placental transfer in rats of 59Fe- and 14C-labelled iron-poly (sorbitol-gluconic acid) complex

The placental transfer of an iron-poly (sorbitol-gluconic acid) complex, Ferastral, has been studied. By use of the 59Fe-, 14C-sorbitol, and 14C-gluconic acid labelled complexes it was shown that the passage of the iron moiety is related to foetal need and that only negligible amounts of 14C from either 14C-sorbitol or 14C-gluconic acid labelled iron complexes were found in the foetus. This implies that the intact complex does not pass the placental barrier.

Studies on an iron-poly(sorbitol-gluconic acid) complex for parenteral treatment of iron deficiency anaemia

A preparation containing an iron-poly(sorbitol-gluconic acid) complex for parenteral treatment of iron deficiency anaemia is described. The physical and chemical properties of the iron complex have been studied by using electrophoresis and gel permeation chromatography. A rapid absorption from the injection site after intramuscular administration to rabbits takes place, 70% of the iron being absorbed after 24-48 hours. Thereafter, the absorption rate is slower, and 32 days after the injection 94% has been absorbed from the injection site. In rabbits the maximum level of iron in serum is reached after 12-24 hours; in dogs after 1-3 hours. Disappearance from the serum takes place slowly. The complex is exclusively absorbed via the lymphatic route. Nine to ten per cent of the given dose is excreted by the kidney within 72 hours in rats and 24 hours in rabbits after intramuscular administration. On administration of the preparation to rats, made anaemic by phlebotomy, a rapid increase of haemoglobin values is observed as well as a very high utilization of the retained amount of the given dose.

Distribution of 59Fe-labelled iron-poly(soribitol-gluconic acid) complex in normal and anaemic rats

An iron carbohydrate complex, iron-poly(sorbitol-gluconic acid), Ferastral, was labelled with 59Fe, and its distribution in rats was studied. The animals were intramuscularly treated with a dose of 10 mg of iron/kg. Three groups of animals were used: group A: non-anaemic and group B: anaemic rats, both kept on iron-deficient diet, and group C: non-anaemic rats kept on iron-supplemented diet. Urinary and faecal excretion, distribution in the body and incorporation in blood of the 59Fe was followed up to 28 days. The total excretion after that time was 15%. There was a rapid initial phase followed by a slower continuous one. After 28 days group A had 25, group B 13 and group C 40% of the given dose remaining at the site of injection. The corresponding values in liver after 28 days were 7, 4 and 17% of the given dose, respectively. In blood a continuous increase was observed. At 28 days after administration 26, 43 and 17% of the given dose had been incorporated in the red blood corpuscles of the respective groups. These results show that the iron complex is absorbed from the site of injection and is utilized for haemoglobin synthesis. They also show that the disposition of the complex is influenced by the iron content of the diet.

The absorption and availability of iron from iron-poly(sorbitol-gluconic acid) complex in rats as measured by phlebotomy

The local and systemic availability of the iron in an iron-poly(sorbitol-gluconic acid) complex (Ferastral) has been studied in rats. The animals were treated intramuscularly with the complex in a dose corresponding to 10 mg of iron per animal. The technique of repeated phlebotomy was used to induce and maintain constant levels of anaemia. The phlebotomies were started immediately after injection and at 14 and 28 days after dosing. At the end of the appropriate interval, the remaining amount of iron at the injection sites as well as the degree of utilization of the iron retained in the animals were estimated. It was shown that the amount of iron at the site of injection of these anaemic animals was less than 3% regardless of the time when the series of phlebotomies were started. It was also shown that the degree of utilization of the iron from the complex was 90% of the retained amount of iron when the phlebotomies immediately followed dosing, and 86% and 79% when initiated 14 days and 28 days respectively. The significance of the decrease in utilization is discussed.

Redressing the Balance in Parkinson’s Disease Management with a Greater Focus on Non-motor Symptoms and Care-giver Health

A more widespread use of questionnaires and scales such as non-motor symptoms (NMS)-Quest and the non-motor symptoms scale (NMSS) has confirmed that NMS, such as sleeping difficulties and speech problems, are at least as troublesome for Parkinson’s disease patients as the major motor symptoms. These NMS can have a profound negative effect on patient quality of life and on the health of the person providing care. This fact is now receiving more attention in clinical practice and measures are being taken to improve the recognition and treatment of NMS, and to provide better support for care-givers. As our knowledge base of NMS expands, we are increasingly finding that some of them, e.g. olfactory deficit and rapid eye movement (REM) sleep behaviour disorder, also occur early in Parkinson’s disease, possibly pre-dating a diagnosis based on motor signs alone.

Influence of thiols on the chlorinating effect of a myeloperoxidase system

The structure-activity relationships for the interactions of a number of sulfhydryl compounds on the transformation of (Z)-3-(4-bromophenyl)-3-(3-pyridyl)allylamine (CPP 200) by an MPO-H2O2-Cl-(-)system at pH 5.25 have been studied. It was found that the inhibitory effect of the thiol group was strongly dependent on the presence of an electron-withdrawing NH3(+)-group in the molecule. Also, the acid-base properties of the thiolic compounds were involved in the inhibitory mechanisms.

(Z)-3-(4-bromophenyl)-3-(3-pyridyl)allylamine as substrate for studies of myeloperoxidase activity

(Z)-3-(4-Bromophenyl)-3-(3-pyridyl)allylamine (CPP 200) is transformed to the corresponding chloroimine by hypochlorite ion (ClO-) formed in the presence of myeloperoxidase. A scheme for this transformation is given. The influence of various compounds on this process has been studied. Cysteamine, cysteine and 6-chloro-3-hydrazino-pyridazine inhibited the transformation of CPP 200, while some p-hydroxyphenyl derivatives increased the rate of transformation of CPP 200. The increase seen on addition of the p-hydroxyphenyl derivatives is not a chloride-dependent reaction. Various mechanisms for the inhibiting effect as well as for the activating effect on the transformation of CPP 200 are discussed.

Influence of various compounds on the degradation of hyaluronic acid by a myeloperoxidase system

Myeloperoxidase in the presence of 0.7 mM hydrogen peroxide degrades hyaluronic by a mechanism which involves iron. Degradation is enhanced in the presence of chloride ion, which is attributed to the formation of hypochlorous acid. Myeloperoxidase-dependent degradation of hyaluronic acid is inhibited by superoxide dismutase, desferrioxamine, iodide ion, bromide ion, mannitol, histidine and various antiinflammatory agents. The destructing agent is presumably the hydroxyl radical.

Near-Field Investigations of the Landers Earthquake Sequence, April to July 1992

The Landers earthquake, which had a moment magnitude (M(w)) of 7.3, was the largest earthquake to strike the contiguous United States in 40 years. This earthquake resulted from the rupture of five major and many minor right-lateral faults near the southern end of the eastern California shear zone, just north of the San Andreas fault. Its M(w) 6.1 preshock and M(w) 6.2 aftershock had their own aftershocks and foreshocks. Surficial geological observations are consistent with local and far-field seismologic observations of the earthquake. Large surficial offsets (as great as 6 meters) and a relatively short rupture length (85 kilometers) are consistent with seismological calculations of a high stress drop (200 bars), which is in turn consistent with an apparently long recurrence interval for these faults.

Myeloperoxidase-oxidase oxidation of cysteamine

Cysteamine oxidation was shown to be catalysed by nanomolar concentrations of myeloperoxidase in a peroxidase-oxidase reaction, i.e. an O2-consuming oxidation of a compound catalysed by peroxidase without H2O2 addition. When auto-oxidation of the thiol was prevented by the metal-ion chelator diethylenetriaminepenta-acetic acid, native, but not heat-inactivated, myeloperoxidase induced changes in the u.v.-light-absorption spectrum of cysteamine. These changes were consistent with disulphide (cystamine) formation. Concomitantly, O2 was consumed and superoxide radical anion formation could be detected by Nitro Blue Tetrazolium reduction. Both superoxide dismutase and catalase inhibited the reaction, whereas the hydroxyl-radical scavengers mannitol and ethanol did not. O2 consumption increased with increasing pH (between pH 6.0 and 8.0), and 50% inhibition was exhibited by about 3 mM-NaCl at pH 7.0 and by about 100 mM-NaCl at pH 8.0. Cysteamine was about 5 times as active (in terms of increased O2 consumption at pH 7.5) as the previously reported peroxidase-oxidase substrates NADPH, dihydroxyfumaric acid and indol-3-ylacetic acid. A possible reaction pathway for the myeloperoxidase-oxidase oxidation of cysteamine is discussed. These results indicate that cysteamine is a very useful substrate for studies on myeloperoxidase-oxidase activity.

Peroxidase and peroxidase-oxidase activities of isolated human myeloperoxidases

Isolated neutrophils from healthy donors were used for the isolation of four highly purified forms of myeloperoxidase as determined by spectral (A430/A280 ratio 0.80-0.87) and enzyme-activity measurements. Although the myeloperoxidases exhibited different elution profiles on cation-exchange chromatography, gel filtration indicated similar relative molecular masses. When these forms were assayed for peroxidase and peroxidase-oxidase activities with several substrates, they all exhibited virtually the same specific activities. These results suggest that possible functional differences between the enzymes may be related to differences in their sites of action rather than to differences in enzyme activity. Myeloperoxidase from a patient with chronic myeloid leukaemia also revealed a similar heterogeneity on cation-exchange chromatography. However, this myeloperoxidase contained in addition one form with a lower and one form with a higher relative molecular mass, as indicated by gel-filtration chromatography.

Alpha-tocopherol and cardiac toxicity of iron

At the onset of disturbances of cardiac rhythm after a 7th injection of iron sorbitol to a patient with severe malabsorption syndrome an extremely low level of alpha-tocopherol in serum--0.04 mg per 100 ml serum--was observed. The clinical manifestations are interpreted as a possible consequence of the depletion of the vitamin, a natural scavenger of free radicals. The possible importance of alpha-tocopherol in preventing the toxic effect of iron on the apparently very sensitive myocardium after parenteral iron to patients with severe malabsorption syndrome is discussed.

Properties of a complex of iron and a sorbitol-gluconic acid polymer for treatment of piglet anaemia

The properties of a complex of iron and a sorbitol-gluconic acid polymer useful for intramuscular treatment of piglet anaemia have been studied. In rabbits it is well absorbed from muscle and a small percentage (8 %) of the administered iron is excreted in the urine. A satisfactory utilization of the administered iron for haemoglobin synthesis has been shown in rats. A high degree of tolerance in piglets was observed also for the highest test doses, 600 mg iron per kg body weight. The clinical utilization was compared to that of iron-dextran using a total of 209 piglets and a dose of 200 mg iron for each animal. Five of these piglets were lost, but these deaths cannot be correlated to the treatment. Of the remaining animals 102 were treated with ISGP and 102 with iron-dextran, and the anaemia-preventing effect was similar for these 2 iron complexes.

Studies on sudden fatalities among piglets following parenteral iron therapy

An investigation was carried out in order to clarify whether there is a correlation between the latent iron-binding capacity, UIBG, in the serum of suckling piglets and sudden fatalities occurring among these animals when they are treated with 250 mg trivalent iron in the form of a complex also containing dextrin, sorbitol, citric acid and lactic acid.

In all, 97 animals from 9 litters were used. By administering 100 mg oral divalent iron to 22 animals, the iron-binding capacity was saturated or appreciably reduced 3 hrs. after the oral treatment. After this time, the animals were treated with parenteral iron. Seventeen other animals were treated with 100 mg divalent iron and immediately afterwards with parenteral iron. Three hrs. later, the iron-binding capacity of the animals was exceeded. In 32 of the control animals, UIBG was high before the parenteral treatment. No fatalities were observed among the animals treated with parenteral iron.

Twenty-three of the animals had a high iron-binding capacity in spite of having diarrhoea. On parenteral treatment of these animals with the iron complex, no fatalities were observed which could be ascribed to the treatment.

The mechanism for the sudden fatalities among suckling piglets after parenteral administration of iron is discussed.