Abstract
INTRODUCTION
Parkinson’s disease (PD), the second most common neurodegenerative disorder, affects 1-2% of people aged ≥65years, increasing to 4% in the aged >80years population [1]. With pharmacological advancements, early stage symptoms are well managed and generally do not result in hospital admissions [2]. As the disease progresses however, motor impairments, non-motor symptoms and higher rates of co-morbidities, lead to increased rates of hospitalisation [2, 3]. As life expectancy in PD patients has increased by up to 5 years since the introduction of dopaminergic medications [4], hospitalisation rates in this population have become significantly higher than that of age matched controls [2, 5]. The resultant economic burden on the health service is large, with an estimated annual cost of € 13.9 billion attributable to PD across Europe [6].
It is currently estimated that 6,000–8,000 people in Ireland have PD [7, 8]. This rate is predicted to double by 2030 [3, 9], resulting in even greater costs to an already struggling health care system. A number of international studies have examined hospital utilisation among the PD population in recent years [10, 11], however there is a paucity of information in an Irish context. This report examines for the first time in Ireland acute hospital in-patient admissions of patients admitted with a known diagnosis of PD between 2009 and 2012. Particularly novel in this context is that data were captured and reported on an annual basis over four years allowing the identification of trends in admissions over time, hitherto unreported in the literature. While a previous international study comprised data from a similar time period, temporal trends were not reported [10]. It is hoped that this data will highlight preventable admissions and inform primary care initiatives to maintain health status in people with PD.
METHODS
Data were obtained from the Hospital Inpatient Enquiry (HIPE) system, the principal repository of national data on discharges from acute hospitals in Ireland [12]. All acute public hospitals nationwide are required to contribute to this database, which is managed by the Healthcare Pricing Office as a mechanism to collect demographic, clinical and administrative information on discharges and deaths from acute hospitals nationally (www.hpo.ie). Data are recorded at discharge for each patient episode of care. Diagnoses are coded using the International Classification of Disease, 10th Edition, Australian Modification (ICD-10-AM), and the Australian Classifications for Health Interventions (ACHI) are used for procedures performed [12]. The data were publicly available and thus considered exempt from full ethical review by a Human Research Ethics Committee (Reference UCD HREC: LS-E-14-113-Lennon).
Data concerning patients with a previously existing (secondary) diagnosis of PD (ICD Codes: G20, G21) were requested from the HIPE database for the years 2009–2012 inclusive. Data governing two age-groups (0–64; 65+) were available. As most people with PD do not receive their diagnosis until they are over 60 and with prevalence increasing with age thereafter [9], this report focuses on the 65+ category, while providing summary data for those under 65. All HIPE discharges from January 1st, 2009 to December 31st, 2012 were coded using ICD-10-AM/ACHI/ACS 6th edition. To ensure consistency in coding, data prior to this were not included. Data beyond 2012 were unavailable at the time of request. The primary categories of interest were the top 10 principal diagnoses on admission, the top 10 principal procedures conducted, admission source and route, and final discharge destination from in-patients episodes. The principal diagnosis is defined as the diagnosis established after study to be chiefly responsible for occasioning the episode of admitted patient care. The principal procedure is that performed for treatment of the principal diagnosis or a diagnostic/exploratory procedure related to the principal diagnosis. A procedure is defined as a clinical intervention that is surgical in nature, carries a procedural risk and/or carries an anaesthetic risk and/or requires specialised training and/or requires special facilities or equipment available in an acute care setting. These are reported to HIPE by the hospital.
Raw data were stored by year in password protected Microsoft Excel spreadsheets. Diagnostic and procedures data were ranked from largest to smallest number of in-patients across the entire four years. Admission type, admission source and discharge destination were expressed as counts and percentages in each calendar year and again summarised over the four year period.
RESULTS
Between 2009 and 2012, a total of 12,437 discharges from acute public hospitals in Republic of Ireland were recorded for people over the age of 65 years and 1,223 for those under 65 years with a previously established diagnosis of PD. Admissions in those under 65 years accounted for less than 9% of all admissions. For those over 65 a steady rise year on year in the number of admissions was noted. No such rise was observed in the under 65 category. In the over 65 age category, 78% (n = 9,679) were emergency admissions, with 87% (n = 8,465) of these admitted via the Accident and Emergency (A & E) department. 82% of over 65 s (n = 10,254) were living at home prior to admission. 25% (n = 7,125) of those who were admitted from their own home were unable to return directly home upon discharge from acute services. A 15% increase in those requiring nursing home (long stay) accommodation (from 12% (n = 1,530) on admission to 27% (n = 3,390) on discharge) was noted. 8% (n = 980) of patients died during their hospital stay. For those with known PD in the under 65 year category, 63% (n = 769) were emergency admissions, with 85% (n = 650) of these admitted via the A & E Department. 87% (n = 1,074) were admitted directly from home. Those requiring long stay accommodation more than doubled from 6% (n = 75) on admission to 13% (n = 154) on discharge. Less than 1% (n = 11) died during their hospital admission. Data detailing cause of death was not made available for this report.
Over 65 age category
Table 1 outlines the 10 most common reasons for admission and principal procedures amongst PD patients over 65 years between 2009 and 2012. The number of admissions per year, bed days per year and average length of stay (ALOS) associated with each diagnosis and procedure are displayed. Data are summed in the final column to provide the total number of admissions and bed days across the entire four years.
Four of the six most common diagnoses can be broadly classified as Diseases of the Respiratory System, accounting for 24% of total PD admissions in the over 65 age category over the 4 year period. Disorders of urinary system (N39) were the second most common primary diagnosis accounting for 6% of total PD admissions in the over 65 s. Fracture of femur (S72) was the primary reason for admission in 3% of those over 65 years. There are large variations year to year in the number of bed days associated with the primary diagnoses as outlined in Table 1. Of note, a 110% increase in the number of bed days attributable to disorders of urinary system from 2009 to 2012 was observed. Similarly, a 38% increase in the number of bed days for unspecified acute lower respiratory tract infections was observed from 2009 to 2012.
Unfortunately data made available did not facilitate analysis of ALOS by place of discharge to determine if this was influenced by those who were unable to be discharged home. Breakdown of results by gender category was not possible with data presented, however a previous comparable study demonstrated no differences between genders in reasons for admission or ALOS in PD [10] disease.
Figure 1 illustrates the trend in admissions for the 5 most prevalent diagnoses in the over 65 age category. An overall increase in admission rates is evident for unspecified acute lower respiratory tract infections, pneumonia (organism unspecified) and disorders of urinary system (other). Admission rates in disorders of urinary symptoms exhibit a steady rise year on year, with an overall 45% increase from 2009 and 2012. A 28% increase in admission rates for unspecified acute lower respiratory tract infections and a 25% increase for pneumonia (organism unspecified) is observed over the same period. No increase in fracture of femur admissions from 2009 to 2012 is noted, however a 15% rise in admission rates is noteworthy between 2009 and 2010.
As summarised in Table 1, over the 4 year period 25% of the over 65 years age group received generalised allied health interventions (physiotherapy, occupational therapy, speech and language therapy and dietetics) as their principal procedure during admission. A breakdown of this data by discipline was not available. CT of brain was the next primary procedure in 13% of all cases. The only orthopaedic procedure to feature in the 10 most prevalent procedures was arthroplasty of hip, reported in 2% of all cases. No procedure was reported in 2,335 cases.
Under 65 age category
Table 2 provides a breakdown of the 5 most prevalent diagnoses and procedures in the under 65 age group. Diseases of the Respiratory System account for 8.5% of admissions in the under 65 category. 3.5% of those under 65years with PD were admitted due to disorders of the urinary system (N39). In 1.8% of the under 65 age group, admission for pain in throat and chest (R07) was the primary reason for admission. Fewer than 5 people under 65 years with PD were admitted each year with fracture of femur (S72), therefore as per HIPE policy, to ensure anonymity, exact data were unavailable.
The principal procedure received during admission for 18% of the under 65 group was generalised allied health interventions. 7% of this cohort underwent a CT brain as their principal procedure. Arthroplasty of hip did not feature in the top 5 principal procedures for this age group, accounting for only 7 cases over the total 4 year period.
DISCUSSION
To the best of our knowledge this is the first study to examine hospital admissions among the known PD population in an Irish context and the first to look at emergent hospitalisation trends over a four year period. As expected, less than 9% of admissions related to the under 65 age category, with a smaller percentage being admitted via an emergency pathway than in the older cohort. Long stay accommodation requirements following acute hospital admission in those with PD in all age categories more than doubled in the four year period. Findley [7] noted that the largest component of costs to the health service in PD are attributable to in-patient care and nursing home stays. In the substantially larger over 65 category a year on year increase in admission rates for the top 10 principal diagnoses is evident. When the findings of this report are considered in this context, notable cost implications to the exchequer must be inferred.
The majority of admissions over the four year period studied were via an emergency pathway (63% in under 65 age group & 78% in 65+). Length of hospital stay has previously been noted in the literature by Low et al. [10] to be 7 days longer for people with PD admitted via a non-elective pathwaywhen compared to controls, again with substantial associated costs. Strategies to reduce emergency admissions and guidelines concerning the monitoring and care-pathway of the PD patient would be welcomed in this regard.
Unsurprisingly, many findings in this study echo previous research. With 62 per cent of persons aged 65 years and over in Ireland reported to have a chronic, lifestyle related illness [13] it is not surprising to note that diagnoses ranked 5–10 for admission to hospital in this age category are related to chronic co-morbid cardiovascular and chronic pulmonary disorders. These diagnoses are not replicated in the under 65 age category. The in-hospital mortality rate of 8% identified, is similar to mortality rates reported by Low et al., and remains significantly higher than age matched (non-PD) counterparts [10]. Infections (urinary and cardiorespiratory), fractures and aspiration pneumonia as the primary causes for hospitalisation in PD identified in this study are echoed elsewhere in the literature [2, 10]. A combination of decreasing mobility, reduced ability to expectorate and PD-related dysphagia contribute to pneumonia’s position as one of the leading causes of death in the PD population [4, 10]. 9% of admissions in the over 65 s were related to pneumonia in this study and accounted for the largest number of bed days (15,206) over the four year period. The contribution of pneumonias to the death rate could not be elicited in this study. When considered in the context of high admission rates in PD for LRTI and concomitant COPD in many cases, strategies to improve the cardiorespiratory health status in the community are warranted to limit hospital admissions. Education on dysphagia signs, symptoms and management in the earlier stages of disease and a focus on early intervention for respiratory infections in primary care is advisable in the elderly PD population to help prevent lengthy, costly hospital admissions and associated morbidity and mortality.
Rates of admissions for urinary disorders in this report are again consistent with the literature. People with PD are more susceptible to urinary tract infections for a variety of reasons including reduced mobility and poor fluid intake [3]. Low et al. [10] have previously determined that people with PD are 2 to 4 times more likely to be admitted to hospital with a UTI than age and sex matched controls. Due to the high rate of urinary disorders requiring hospital admission now established in the Irish PD population, prevention and early management strategies warrant consideration. Arasalingam & Clarke [3] have previously recommended that PD patients with recurrent UTIs should be considered for low dose prophylactic antibiotics, to prevent UTI related hospital admissions. However, to date no evidence is available to support this proposition or alternate prevention strategies.
The mainstay of treatment for the principal diagnoses of respiratory or urinary infections remains pharmacotherapy, which is not categorised as a procedure. Direct referral to physiotherapy to aid in secretion clearance and mobilisation for respiratory infection and speech and language therapy for dysphagia diagnosis and management may, in part, contribute to allied health interventions cited as the principal procedure received during admission. While it is not possible to determine directly from the data presented, it is likely that acute hospital admissions are used as an opportunity for patients to access rehabilitation expertise, intervention and/or management strategies. Again, one cannot directly infer from the data whether this delays discharge and contributes to the total bed days by diagnosis. In a comparable UK study [10] the ALOS attributable to pneumonia in the over 65 age category was 16 days compared with 22 days identified in this study (when pneumonia (unspecified) and aspiration pneumonia were combined). This suggests that the hospital stay in Ireland was longer than required to treat the infection alone. While reasons for delayed discharge such as accessing rehabilitation or awaiting long term care placement may be considered as possible factors in this context, it is interesting to note that when comparing ALOS for urinary tract infection in this study with the UK report [10], data were directly comparable. Both studies reported the ALOS as 16 days in the over 65 age category.
Risk of falls and poor bone integrity have previously been highlighted as an area of concern in the PD population [14], with research demonstrating a 2.6 to 4 fold risk of sustaining fractures of the proximal femur in PD patients compared to age matched healthy controls [14]. Our investigation shows that fracture of femur is the 4th most common reason for hospital admission in the elderly Irish PD population. This diagnosis accounts for the longest average length of stay among PD patients (30.02 days), amounting to a total of 11,886 bed days over the four years examined. It has previously been reported that people with PD who suffer geriatric hip fractures will encounter more complications and be discharged to nursing homes twice as often as non-affected controls [14], again highlighting the need for targeted rehabilitation strategies and careful discharge planning for this population. Preventive strategies to reduce falls risk in the PD population, thereby reducing hospital admissions would be the most cost effective strategy. From an Irish perspective it would seem salient to incorporate a PD specific strategy under the auspices of the National Falls and Bone Health Strategy (2013) in order to reduce the falls risk in this vulnerable population. The relatively stable rates of hospital admission rates for fractured femur observed over the four year period in this study, in contrast to increasing trends in other diagnostic categories, may already reflect some of the primary care falls prevention strategies currently in situ. The spike of fracture admissions noted in 2010 may be attributed to the adverse weather conditions experienced in Ireland that year as abnormally high fracture rates were identified in the general population [16].
Noticeably, diagnoses of infections and pneumonias remain the main causes of admission to acute hospitals in the younger PD age category. While the diagnosis of pain in throat and chest (R07) is suggestive of cardiac investigations to out rule an acute myocardial infarction amongst other pathologies, no chronic co-morbidities such as COPD and heart disease diagnoses are evident, in contrast with the older age group. Another difference between the age groups is the low prevalence of femur fractures in the younger age group.
As is evident from results presented here, allied health interventions including physiotherapy are the most common procedure reported in both under and over 65 s in this cohort in the acute hospital setting. The refocus of some of these services to the community setting to maintain mobility and manage dysphagia proactively may be a more cost-effective strategy in the longer term. Four of the five most prevalent diagnoses followed a trend towards increased admission rates, including pneumonia, UTIs, aspiration pneumonia, and LRTI (See Fig. 1). It is undetermined whether this increase is due to an increased prevalence of people with PD in the population, ineffective community-based management strategies or a combination of both. However, it is clear that the specific needs of people with PD warrant careful consideration in primary care service planning for the elderly to reverse this trend.
Conclusion
Pneumonia, infection and femur fracture are the principal reasons for in-patient admissions for elderly patients with PD in the Republic of Ireland. A worrying trend in increased hospital admission rates for pneumonia and infection exists. With the recent shift towards management of chronic diseases in community and primary care settings, it is imperative to include targeted programmes for the expanding PD population aimed at maintaining and/or improving mobility, early screening and intervention for dysphagia, timely interventions for respiratory and urinary tract infections are required.
Limitations
A number of limitations should be taken into account when interpreting the results of this study. The authors rely on coded data with potential for inaccuracies in the coding systems, for over estimating procedures [17] and human error in data input. However quality assurance developments for coded records in the HIPE system have improved in more recent years [18] and reliability data from a comparator population using HIPE data suggest acceptable agreement rates for diagnosis and procedures of kappa 0.82 (95% CI 0.75–0.89) and kappa 0.91 (95% CI 0.88–0.94) [19] respectively. Summary data made available to the researchers did not allow break down by gender, additional age categories, type of PD (e.g. idiopathic, vascular, drug-induced or atypical) or staging of disease. Furthermore data could not be linked across items reported to allow, for example, the principal diagnoses or ALOS to be linked to the admission source or discharge destination. Additionally data relate to discrete episodes of care without the ability to monitor readmission rates. Finally, the lack of age matched controls or disease specific comparator group limits the ability to draw conclusions regarding differences in service use among people with PD and age matched counterparts.
CONFLICT OF INTEREST
The authors have no conflicts of interest to declare.