Economic burden of Huntington’s disease in Peru

Huntington’s disease (HD) is a monogenetic, neurodegenerative disorder that leads to progressive disability and eventually to full dependence [1]. Age at onset spans from early childhood to senescence, although typical HD onset occurs in middle-aged patients [2]. HD symptoms are characterized by the triad of choreic movements, cognitive impairment, and psychiatric symptoms [3]. A variety of non-neurological clinical features are also associated, which therefore requires multidisciplinary and integrated clinical care [4] in order to improve quality of life and to reduce premature mortality [5].

The worldwide HD prevalence is estimated at 2.71 per 100,000 inhabitants [6], with wide variations among different regions [7]. There is a significant HD population in Latin America, mostly concentrated in Venezuela, Colombia, Peru and Brazil [8]. In Peru, there have been country-wide reports of HD, although the majority of patients are located in the capital city of Lima and in the Valley of Cañete (a HD hotspot with an estimated prevalence of 40 cases per 100,000 inhabitants) [9, 10]. According to a 2014 annual report, there have been at least 100 HD families diagnosed and currently receiving follow-up at the Neurogenetics Research Center at the Instituto Nacional de Ciencias Neurológicas (NRC-INCN), which is the only existing Peruvian center providing genetic testing for HD [11].

Despite the high prevalence of HD in Peru, public healthcare funding for HD patients is not a priority. In 2013, the Peruvian government promulgated a law declaring healthcare for rare disorders of high priority [12]; subsequently, the Ministry of Health of Peru (MINSA) developed a prioritized list of 399 rare diseases, with the recommendation to provide extra funding only to the top 8 [13]. HD ranks in the 297th position on the MINSA list, which means that it is not receiving this additional financial support.

Roughly 80% of the Peruvian population has health insurance of any kind [14]. The health care system comprises five subsystems [15, 16]: a) the MINSA subsystem, that provides health services to the poor and extremely poor (51% of the total population), although the full range of healthcare services (medical appointments, hospitalization, diagnostic tests and drugs) are only fully subsidized for SIS (integral health insurance) affiliated patients; thus, out of pocket payments are required for non-SIS affiliated patients; b) the Social Security Health subsystem (ESSALUD), which provides health services to the salaried and their dependents (26.7% of the population), run by the Ministry of Labor; c) the Armed Forces healthcare subsystem, run by the Ministry of Defense; d) the Police Forces healthcare subsystem, provided by the Home Office and e) a private healthcare subsystem covering approximately 1.8% of the population. Each subsystem consists of an independent legal framework, health coverage benefits, a technological infrastructure, and a network of healthcare centers and hospitals. Even for those having governmental insurance, cumbersome reference paperwork for insurance approval stands to hinder patients from receiving full coverage for many healthcare services. In Peru, technically there are no copayments in public healthcare. Even those drugs and medical devices which are directly provided by health care centers are for free, although if the patient has to purchase them in the pharmacy, he/she must pay the whole price.

Research regarding HD costs is very scarce [17, 18]. Furthermore, in Latin America and more specifically in Peru, there has been no research aimed at quantifying HD costs or defining the disease’s economic burden on afflicted patients. Our study aims to estimate direct and indirect costs of HD in Peru from a societal perspective, examining the economic impacts on both the healthcare system and on patients, and also on the economy as a whole, since we also compute productivity losses due to HD. To our knowledge, this study is the first to examine the economic burden of HD in Peru. It is our hope that it will contribute to fully understand the economic consequences of this disease in an effort to highlight the need for HD to become more of a priority for the Peruvian health care system.

The typical HD patient interviewed was an adult woman in a parental role who lived in the capital city of Lima. Higher prevalence of HD in Peruvian women was also found by Cornejo-Olivas et al. (2015) [10]. However, the relative higher frequency of female on the HD cohort we followed might do not reflect a real difference in HD population in Peru, and would be mostly related to demographic characteristics of outpatient HD population followed at the NRC, with less patients very ill and milder forms of HD. One of the characteristics of HD is that it appears when patients have already formed a family and have offspring [2, 3]. The mean age at onset in our population is consistent with classical reports among the majority of other worldwide HD cohorts previously reported on [28, 29]. Furthermore, the high percentage of our population reporting official residence in Lima is likely related to the fact that the NRC-INCN is the national referral center for HD in the public healthcare system [30].

According to our results, HD patients seemed to be affiliated with any health insurance in a lower proportion than the rest of Peruvian population. Therefore, they could be considered as a highly vulnerable group. Among patients working at the time of the interview, more than 76% declared their job as informal, which means that they did not have any work-associated benefits like health insurance coverage or a retirement pension. It may seem paradoxical that patients with Barthel 1, 2 or 3 in our cohort had, on average, similar salary losses than more independent patients (Barthel 4 or 5). This particular finding might be related to the fact that patients with higher disability might have lost their jobs a long time before the interview. Also, this result may be due to a sample bias, since the Barthel 1 category comprises a very small number of patients.

Up to 69% of the interviewed patients had a parental role and their HD status affected their ability to contribute to home expenses. The diagnosis of HD in one family member triggers many changes at home, often forcing another family member to take over the role of the person diagnosed with HD [31, 32]. Moreover, most patients need some kind of assistance to develop basic or instrumental activities of daily living, also leading to those closer relatives becoming the primary caregivers since the public social services network in Peru is virtually non-existent. Also, the cost of professional caregivers providing continued formal care is out of reach of most Peruvians and, in particular, of the patients in our sample, which explains that this kind of care was not reported. As was described in the results’ section, informal caregiving tends to increase with patients’ level of dependency. It is worth noting, however, that the total cost of informal caregiving services is higher in the Barthel 2 group (severe dependency) as compared with the Barthel 1 group (total dependency). This is related to the fact that most disabled HD patients are usually mute and confined to bed, thus requiring fewer hours of assistance in activities of daily living in comparison with those HD patients who are still walking.

The high percentage of informal caregiving costs shown in our study exceeds the one obtained in a United Kingdom study of a parallel HD cohort performed by Jones et al. [18], in which informal care of HD accounted for 65% of total costs. This fact may be related to the reduced size of the market of formal care in Peru. It also has to be highlightened that HD progressively generates motor disfunction (difficulties for walking, writing, dressing, feeding), cognitive (executive dysfunction, learning disability, memory loss, planning difficulties) and behavioral disturbances (apathy, hallucinations, depression, obsessive-compulsive behavior, suicidal behavior) [33]. Cost studies for Alzheimer’s Disease and other diseases causing severe dependency for activities of daily living also reported comparable results [23, 34].

By contrast, healthcare costs represented only 7.3% of total costs. The average cost reached USD 590 in 2015, almost twice the total health care expenditure per inhabitant in Peru in the same year (USD 314) [35]. As anticipated, healthcare costs increased in parallel with increases in patient dependency, in line with previous literature [17]. With regard to medical visits, most of our patients only reported follow-up visits with neurology/neurogenetics, contrasting with national and international HD guidelines. These guidelines recommend an integral healthcare strategy for HD patients that includes, in conjunction with symptomatic pharmacological therapies, regular visits to neurologists, geneticists, psychiatrists/psychologists, endocrinologists, gastroenterologists, nutritionists, rehabilitation specialists and general practitioners, among others [36, 37].

Almost all interviewed patients had to finance healthcare costs out-of-pocket, despite most of them technically being enrolled in some form of public health insurance. It is worth noting that INCN is the usual provider of healthcare services for HD patients, and that these services may only be provided for free to those citizens who are covered by the SIS (integral health insurance). Even so, patients are forced to deal with the bureaucracy of SIS, which requires extensive referral documentation and additional paperwork to be completed beforehand, and also leads to months-long waits for reimbursements. Since most patients opted to finance healthcare costs out-of-pocket and did not pursue SIS reimbursement given logistical constraints, it is reasonable to assume that they only could afford high priority drugs and medical visits. This fact could explain the large proportion of reported neurology follow-up visits versus visits to other physicians.

Our study has a number of limitations. Firstly, it is possible that a certain number of HD patients residing in provinces with challenging environments, such as the highlands or jungle, have limited access to molecular diagnosis due to geographical barriers, which would thus contribute to sample bias. Nevertheless, as was shown in the results’ section, there is a reasonable geographic spread in our sample. Secondly, since the use of health services depends mostly on the spending capacity of patients and their families rather than on optimal healthcare requirements, healthcare costs will be underestimated relative to what appropriate treatment would require. Thirdly, we cannot provide a sensitivity test for our estimations of informal care costs by using an opportunity cost method, since socio-demographic and labour status data were only collected for the main caregiver. Finally, external validity of our study may also be limited as our sample derives from a population registered in the NRC-INCN, which does not necessarily represent the entirety of the Peruvian HD population. However, since the NRC-INCN is the only national reference center for molecular diagnosis of HD in the public system, almost every Peruvian patient with a clinical suspicion for HD is referred to this center in order to determine a definitive diagnosis.

As there is no national registry of HD prevalence in Peru, we cannot make an accurate calculation of societal cost of HD. However, we may estimate a low threshold by assuming that the national prevalence is in line with the minimal prevalence rate reported for Latin America (0.35 per 100,000 inhabitants, based on the community-based prevalence of HD in Venezuela) [7] and by taking into consideration that the estimated prevalence in the Valley of Cañete (a known HD focus) is 40 per 100,000 inhabitants [9]. Therefore, we can estimate that the total annual cost of HD for Peruvian society reached about USD 1.2 million in 2015, with direct healthcare costs accounting for around USD 85 thousand. This latter amount only represents 0.15% of the total budget allocated in 2015 to the Intangible Solidarity Health Fund (FISSAL), which is the public agency in charge of financing high cost and rare diseases. However, today HD is excluded from the list of the eight high priority rare diseases covered by the FISSAL.

According to our results, 98.2% of direct healthcare costs and 100% of direct non-healthcare costs are borne by patients and their families. Medical care costs represent, on average, 19.3% of the annual equivalent household income, but it dramatically increases with patients’ dependency degree (from 14.7% for Barthel 4 and 5 to 25.2% for Barthel 3, and 85.4% for most disabled patients --Barthel 1 and 2-). WHO defines as catastrophic those health expenditure “greater than or equal to 40% of a household’s non-subsistence income, i.e. income available after basic needs have been met” [38]. Therefore, we conclude that the impact of HD cost on patients and their families is high, and catastrophic for most dependent patients. Aside from the significant economic barriers, patients with HD also suffer from a lack of appropriate access to integral care due to the existence of geographical and administrative barriers, and also due to the limited supply of specialized medical services in the Peruvian healthcare system.

Additional federal funding for this rare disease would therefore significantly reduce the out-of-pocket payments for HD patients and allow them to receive the needed level of care for optimal disease management. Thus, it is our hope that defining the economic impact of HD on patients and their families will help pave the way for the development of new health policies that aim to more appropriately address the health and social needs of this vulnerable population.