Table 1.
Studies that examined prescribing patterns of PD medications.
| Study | Country | Type of study and source of data | PD case ascertainment | Year | Setting | Number of patients and/or prescriptions | Unit of analysis | Prescribing determinants | Comments/main findings | Quality score (out of 10) |
|---|---|---|---|---|---|---|---|---|---|---|
| Ezat et al. [41] | Norway | Retrospective study from three hospitals in Norway | PD diagnosis confirmed by clinical experts | 2009–2013 No comparison |
Inpatient setting | 262 patients | Number of patients treated per 100,000 inhabitants | Geographical location | Out of all PD medication, the study examined prescribing of L-dopa intestinal gel alone. There is a significant variation of L-dopa intestinal gel prescribing in Norwegian counties (Rosalind county has the highest rate of prescribing). |
3 |
|
| ||||||||||
| Tripathi et al. [42] | India | Retrospective chart review from a neurology clinic in India | PD diagnosis confirmed by clinical experts | 2014 No comparison |
Community | 100 patients | Percentage of patients prescribed each drug/drug class/drug combinations | N/A | L-dopa monotherapy is the most commonly prescribed regimen. L-dopa + anticholinergic is the second most common regimen followed by L-dopa + DA. |
4 |
|
| ||||||||||
| Surathi et al. [43] | India | Cross-sectional prescription review study | PD diagnosis confirmed by clinical experts | 2011–2014 No comparison |
Community | 800 patients | Percentage of patients prescribed each drug/drug class/drug combinations | N/A | L-dopa monotherapy is the most commonly prescribed regimen. Anticholinergic is the second most common regimen. |
4 |
|
| ||||||||||
| Jost et al. [44] | Germany | Cross-sectional surveys with patients and physicians. | PD diagnosis confirmed by clinical experts | 2017 | Community | 4485 patients, and 271 physicians | Percentage of patients prescribed each drug/drug class/drug combinations | N/A | The most commonly prescribed medication is L-dopa (90.27%) followed by DAs (40.66%). | 4 |
| Dahodwala et al. [45] | USA | Retrospective cohort from a random sample of annual 5% Medicare Parts A and B claim | Reimbursement data using ICD-9 code. There were efforts to exclude atypical parkinsonism by excluding patients with history of atypical parkinsonism |
2007–2010 No comparison |
Inpatient and community settings | 9482 to 9626 patients | Percentage of patients prescribed each drug/drug class/drug combinations | Age, gender, race, income, comorbidities, and neurology clinic visits. | Most PD patients receive PD medications. African Americans and patients not seen by neurologists are undertreated. |
9 |
|
| ||||||||||
| Liu et al. [46] | Taiwan | Retrospective cohort from Taiwan National Health Insurance Database | Reimbursement data using ICD-9 code. There were efforts to exclude atypical parkinsonism by excluding patients with history of atypical parkinsonism |
2004/2011 | Community | 19,302 patients in 2004 and 41,606 patients in 2011 | Percentage of prescriptions. (one prescription may include more than one prescribed medication) | Age | General increase in L-dopa monotherapy prescribing. More than doubling of DA prescribing for younger patients. Most of the DA prescriptions are non-ergot derivatives after 2008. |
8 |
|
| ||||||||||
| Keränen and Virta [47] | Finland | Retrospective cohort from a drug insurance reimbursement register | Reimbursement data using ICD-10 code. The reimbursement data were not validated against patient charts. |
2005/2012 | Community | 1436 patients in 2005 and 1607 patients in 2012 | Percentage of patients prescribed each drug/drug class | Age | L-dopa is the most prescribed medication in patients aged >75 y. DAs and MOA-B inhibitors are the most prescribed medications in patients aged <60 y. Prescribing changes are in accordance with changes in guidelines. |
4 |
| Hand et al. [48] | England | Retrospective study used The Northumbria Healthcare NHS Foundation Trust PD service | PD clinic data. Atypical parkinsonism included, such as multiple system atrophy (MSA) and progressive supranuclear palsy (PSP). |
2015 | Community and care home settings | 377 patients | Percentage of patients prescribed each drug/drug class/drug combinations and L-dopa equivalent daily dose (LEDD) | Care settings | Age and disease stage were higher in those living in care homes. LEDD was lower in those living in care homes. Older age, LEDD, and severe disease stage were significantly associated with care home placement. Use of DAs, MAO-B inhibitors, and COMT inhibitors was higher in patients living in their homes. |
6 |
|
| ||||||||||
| Degli Esposti et al. [50] | Italy | This retrospective study used databases of three Italian Local Health Authorities | Data linkage study. There were efforts to exclude atypical parkinsonism by linking prescription data to hospital data. |
2009–2011 No comparison |
Inpatient and community settings | 1607 patients on selegiline or rasagiline | Percentage of patients prescribed each drug/drug class/drug combinations | Age and gender | 63.3% of patients were on selegiline while 36.2% were on rasagiline. DAs and L-dopa were more prescribed in rasagiline group. |
5 |
|
| ||||||||||
| Crispo et al. [51] | USA | Retrospective cohort from the Cerner Health Facts database | Hospital diagnosis ICD-9 code. There were efforts to exclude atypical parkinsonism by excluding patients ages less than 40 years |
2001/2011 | Inpatient | 16,785 patients | Percentage of patients prescribed each drug/drug class | Age and gender | L-dopa was the most prescribed medication from 2001 to 2011. Decline in DA use over 2007–2011. Stable rate of DA use in patients aged ≥80 y over 2001–2011. |
7 |
| Pitcher et al. [53] | New Zealand | Retrospective cohort from national prescription database in New Zealand | Drug sales database. No efforts to exclude atypical parkinsonism. |
1995/2011 | Community and rest (care) homes. No comparison. | N/A | Defined daily doses (DDD) per 1000 inhabitants per day | N/A | General increase in L-dopa prescribing over 1995–2011. Slight decrease in DA prescribing over the same interval. Slight increase in COMT inhibitor and amantadine prescribing. An increase in pergolide prescriptions even after 2007. |
3 |
|
| ||||||||||
| Nakaoka et al. [54] | Japan | Retrospective cohort from medical claim database in JMDC, Tokyo, Japan | Reimbursement data using ICD-10 code. There were efforts to exclude atypical parkinsonism by excluding patients aged <30 years |
2005/2010 | Inpatient and community settings | 714 patients | Percentage of patients prescribed each drug/drug class | Age. | L-dopa is the most prescribed medication over 2005–2010. Of newly diagnosed patients, 30% are prescribed anticholinergics. Non-ergot DA prescribing increases after 2007 in accordance with label revision of ergot DAs. |
8 |
|
| ||||||||||
| Junjaiah et al. [55] | India | Prospective study that included interviews with PD patients | PD diagnosis confirmed by clinical experts | 2011–2013 No comparison |
Community | 100 patients | Percentage of patients prescribed each drug/drug class/drug combinations | Disease duration | 48% of PD patients received L-dopa alone. 52% of PD patients received combination therapies. |
5 |
| Guo et al. [56] | Taiwan | Retrospective study used the National Health Insurance Research Database of Taiwan | Reimbursement data using ICD-9 code. There were efforts to exclude atypical parkinsonism by excluding patients who used drugs inducing parkinsonism |
2000–2005/2006–2010 | Inpatient and community settings | 1645 patients | Percentage of patients prescribed each drug/drug class/drug combinations | Age, gender, prescriber type, and interval between PD diagnosis and starting medication | The study examined the initial therapy for newly PD diagnosed patients. L-dopa monotherapy is the most commonly prescribed regimen. DAs were prescribed mainly by neurologists. |
7 |
|
| ||||||||||
| Gaida et al. [57] | South Africa | Retrospective cohort from national community pharmacy group in South Africa | Drug sales database. There were efforts to exclude atypical parkinsonism by excluding patients aged <50 years |
2010 No comparison |
Community | 5,168 patients and 25,523 prescriptions. | Percentage of prescriptions | Age and gender. | The most commonly prescribed medications are L-dopa + COMT inhibitors. The second most commonly prescribed medications are non-ergot DAs. Patients aged 50–59 y are prescribed DAs more than L-dopa while >70 y group are prescribed more L-dopa. |
5 |
|
| ||||||||||
| Skogar et al. [84] | Sweden and Norway | Using questionnaires with PD patients and drug registry data | No efforts to exclude atypical parkinsonism. | 2010–2013 No comparison |
Community | 1553 patients in Sweden and 1244 patients in Norway | Percentage of patients prescribed each drug/drug class/drug combinations | NA | L-dopa products were the most commonly used PD medications in both countries. Selegiline was significantly used more in Norway than in Sweden. |
4 |
| Morrish [58] | England | Retrospective study that used online statistics at the National Health Service (NHS) Information Centre | Drug sales data. No efforts to exclude atypical parkinsonism |
1999/2010 | All drug sales in both inpatients and community settings | N/A | Total net ingredient cost for PD medication in pound (£) | N/A | The total net ingredient cost of PD medication was increased from £37 million in 1998 to £130 million in 2010. DAs accounted for the largest portion of overall spending growth. A static spending was seen in L-dopa products. There was a decrease in ergot-DAs spending especially after 2004. |
3 |
|
| ||||||||||
| Hattor et al. [59] | USA/Japan | Using questionnaires with PD patients followed by interviews with PD patients. | No efforts to exclude atypical parkinsonism. | 2003 in USA and 2008 in Japan | Community | 300/3548 patients | Percentage of patients prescribed each drug/drug class/drug combinations | Drug side effects. | Patients who had already experienced dyskinesia were less concerned about L-dopa dyskinesia. The most commonly prescribed medication was L-dopa in both countries followed by DAs. |
2 |
|
| ||||||||||
| Schroder et al. [60] | Germany | A cross-sectional survey of neurologists | PD diagnosis confirmed by clinical experts | 2004 No comparison |
Inpatient and community settings | 60 neurologists complete the medical charts of 320 patients. | Percentage of patients prescribed each drug/drug class/drug combinations | Age and disease severity | 53% of patients aged <70 years were used DAs without L-dopa. In patients aged >70 years, 50–52% were used L-dopa without dopamine agonists. |
5 |
|
| ||||||||||
| Ooba et al. [61] | Japan | Retrospective study used the National Japanese database vendor | Reimbursement data using ICD-10 code. There were efforts to exclude atypical parkinsonism by excluding patients aged <40 years |
2005/2008 | Inpatient and community settings | 547 patients | Percentage of patients prescribed each drug/drug class/drug combinations | Age, gender, and pergolide withdrawal from the USA market in 2007 | Percentage of patients prescribed cabergoline or pergolide did not decrease; rather, it tended to increase after 2007. | 5 |
| Hollingworth et al. [62] | Australia | Retrospective study using prescription data from Medicare Australia and Drug Utilisation Sub-Committee (DUSC) databases | Reimbursement data. No efforts to exclude atypical parkinsonism |
1995/2009 | Community | 5,078,242 prescriptions | Defined daily doses (DDD) per 1000 inhabitants per day | Age, gender, and type of prescriber | Decline in anticholinergics and DAs over 14 years. General increase in L-dopa use over 14 years. An increase in pramipexole prescribing after 2008. |
4 |
|
| ||||||||||
| Fayard et al. [63] | France | A population-based study that included interviews with PD patients | PD diagnosis confirmed by clinical experts | ≤2000–>2000 | Community | 308 patients | Percentage of patients prescribed each drug/drug class/drug combinations | Age and type of prescriber. | Agreement with the French recommendations increased after 2000 compared to before 2000. For patients aged <60 years, 35% increase in DAs prescribing after 2000. For patients aged >70 years, about 1% increase in L-dopa prescribing after 2000. | 8 |
|
| ||||||||||
| Wei et al. [64] | USA | Retrospective study used the Medicare Current Beneficiary Survey and Medicare claims | Reimbursement data using ICD-9 code. The reimbursement data were not validated against patients' charts. |
2000–2003 No comparison |
Inpatient, community, and nursing home settings | 571 patients | Percentage of person-years prescribed each drug/drug class/drug combinations | Age, sex, race, education, marital status, annual income, care setting, and comorbidity scores. | Half of the patients did not use any PD medication in the period of the study. L-dopa was the most PD medication prescribed as a monotherapy or as a combination therapy. Age, prescription drug coverage, residing in an institution, education, dementia, and depression had an effect on PD medication use. |
5 |
| Rosa et al. [65] | Europe | Retrospective study that used “intercontinental marketing services” health and examined antiparkinsonian sales in 26 European countries | Drug sales data. No efforts to exclude atypical parkinsonism |
2003/2007 | Community | A value of 663 million antiparkinsonian consumption in 2003 and 717 million in 2007 | Defined daily doses (DDD) per 1000 inhabitants per day | N/A | Levodopa and DAs accounted for half of the drug use in most countries. Between 2003 and 2007, the hugest increase in sales occurred with L-dopa and MAO-B inhibitors. Heterogeneity was seen in the use of PD medications in Europe. |
5 |
|
| ||||||||||
| Trifiro et al. [66] | Italy | Retrospective study used the Arianna database (GPs database) | GPs and prescription data. GP data were not validated against patients' charts. |
2003/2005 | Community | 1479 patients | Percentage of patients prescribed each drug/drug class/drug combinations | Age | Stable prevalence of PD medication use during the years of the study. L-dopa was the most PD medication prescribed as a monotherapy or as a combination therapy. Non-ergot DAs use was increased in 2005, especially in elderly people. |
6 |
|
| ||||||||||
| Osinaga et al. [67] | Spain | Retrospective study used the ECOM database of the Spanish Ministry of Health | Drug sales data. No efforts to exclude atypical parkinsonism |
1992/2004 | Community | N/A | Defined daily doses (DDD) per 1000 inhabitants per day | N/A | L-dopa was the most prescribed PD medication. Consumption of PD medications has increased during the years of the study. |
4 |
| Swarztrauber et al. [68] | USA | Retrospective study used the Pacific Northwest Veterans Health Administration (VHA) Data Warehouse | Administrative data using ICD-9 code. The data were validated against patient charts by a neurologist. |
1998–2004 No comparison |
Community | 530 patients | Percentage of patients prescribed each drug/drug class/drug combinations | Age and type of prescriber | 29% of the initial antiparkinsonian therapy was initiated by neurologists. 20% of patients younger than 65 years received DAs. Initial antiparkinsonian therapy is strongly influenced by the prescriber's specialty. Additionally, it is mostly initiated by primary care physicians (without PD expertise). |
7 |
|
| ||||||||||
| Huse et al. [69] | USA | Retrospective study used MedStat's MarketScan Research Databases | Drug registry data using ICD-9 code. No efforts to exclude atypical parkinsonism |
1999–2001 No comparison |
Community | 4846 patients | Percentage of patients prescribed each drug/drug class/drug combinations | Age, gender, comorbidity (Charlson index), and type of insurance. | L-dopa was the most prescribed PD medication as a monotherapy or as a combination therapy regardless of age or type of insurance. DAs are the second most prescribed PD medication, but it only accounted for about 15% of patients younger than 65 years. |
6 |
| Tan et al. [70] | Singapore | Retrospective study used patients' charts at a tertiary referral centre. Then factors that influence neurologists' decisions were examined by surveying a sample of neurologists. | PD diagnosis confirmed by clinical experts | N/A | Community | 306 patients. 11 neurologists participated in the survey. |
Percentage of patients prescribed each drug/drug class/drug combinations | Age, disease severity, intolerance of side effects, drug side effects, drug availability, clinical experience with the drug, drug cost, patient preference, and drug company sponsorship | 92.3% of patients were on L-dopa. Most of the patients who were on L-dopa were older and had a higher stage of PD severity scale (Hoen and Yahr). 26.8% of patients were on DAs. From surveying the neurologists, the most important factors influencing their prescribing behaviors were severity of symptoms, intolerance of side effects, and efficacy. The real prescribing behaviours showed a significant positive association of medication usage with cost subsidy by the hospital. There was no mention in the manuscript when this study was conducted, although it was published in 2005. |
8 |
|
| ||||||||||
| Grandas and Kulisevsky [71] | Spain | A population-based study that included surveying 241 physicians | PD diagnosis confirmed by clinical experts | 1999 | Community | 1803 patients and 241 physicians | Percentage of patients prescribed each drug/drug class/drug combinations | Type of prescriber | L-dopa was the most prescribed PD medication (90.4%) regardless of type of prescriber. DAs were the second common PD medication prescribed (44%). Movement disorder specialists tended to prescribe DAs and COMT inhibitors more than other prescribers followed by neurologists. General physicians used to prescribe anticholinergics more than other prescribers. |
6 |
|
| ||||||||||
| Askmark et al. [72] | Sweden | Retrospective study that used the prescription sales of 906 community pharmacies and 89 hospital pharmacies. | Drug sales data. PD diagnosis confirmed by clinical experts. |
1995/2001 | Inpatient and community settings | N/A | Defined daily doses (DDD) per 1000 inhabitants per day | Age and number of neurologists in a particular county | Between 1995 and 2001, L-dopa prescriptions sales increased. After 1997, there has been an increase in sales of DAs (cabergoline, pramipexole, and ropinirole). There was no correlation between the sales of all PD medications and the densities of neurologists or population ages in any particulate county in the study. |
5 |
| Leoni et al. [73] | Italy | Cross-sectional surveys with patients. | PD diagnosis confirmed by clinical experts. | 1997–1998 No comparison | Community | 130 patients | Percentage of patients prescribed each drug/drug class/drug combinations | Age, disease severity, and duration of the disease | L-dopa was the most prescribed PD medication (98.5%) followed by DAs (43.7%). Use of PD medications increased with duration and severity of the disease. Increased age is associated with increased use of PD medications. | 7 |
|
| ||||||||||
| Lapane et al. [83] | USA | Retrospective study that used (systematic assessment of geriatric drug use via epidemiology) database in 5 states in USA. | Clinical database. Atypical parkinsonism, included such as multiple system atrophy (MSA), and progressive supranuclear palsy (PSP). |
1992–1996 No comparison |
Nursing homes | 24,402 patients | Percentage of patients prescribed each drug/drug class/drug combinations | Gender, race, age and cognitive function | 44% of all PD patients in nursing homes received one of the PD medications. DAs were the most common PD medications prescribed (75%) followed by L-dopa (52.27%), MAO-B inhibitor (20.45%), and anticholinergics (18.18). Female, African Americans, and older age patients were less likely to receive PD medication in nursing homes. |
7 |
| Fukunaga et al. [74] | Japan | Cross-sectional surveys with patients. | PD diagnosis confirmed by clinical experts. | 1994–1996 No comparison |
Inpatient and community settings | 104 patients | Percentage of patients prescribed each drug/drug class/drug combinations | Duration of the disease | L-dopa was the most prescribed PD medication (78.84%) followed by DAs (76.92%). Combination therapies (2-3 PD medications) were common in patients with duration of disease less than 5 years. The combination therapy of 4 PD medications was common in patients with duration of disease of 7–9 years. |
4 |
|
| ||||||||||
| Menniti-Ippolito et al. [75] | Italy | Retrospective study that used prescriptions of drugs included in the National Drug Formulary | Atypical parkinsonism, including such as multiple system atrophy (MSA), and progressive supranuclear palsy (PSP). | 1986–1991 No comparison |
Community | 6572 patients | Percentage of patients prescribed each drug/drug class/drug combinations | N/A | L-dopa was the most PD medication prescribed (86.2%) followed by selegiline (24.6%). The main aim of this study was to estimate the prevalence of PD by using the number of patients who used PD medications. |
6 |