Discharge outcomes among elderly patients undergoing emergency abdominal surgery: registry study of discharge data from Irish public hospitals

Older patients who undergo intra-abdominal surgery are often frail and have complicating underlying medical comorbidities [1‐4] which mean these operations are associated with significant post-operative morbidity and mortality [5]. In contrast to planned surgery, there is less time to prepare emergency patients preoperatively, although such preparations would be valuable in this patient group [6]. As a consequence, older patients are vulnerable to post-operative functional decline that can have an impact upon quality of life [7]. Temporary or permanent changes in their care needs after surgery may have profound implications for patients, family and carers, and society.

The configuration of Irish publically-funded healthcare services, and data available from administrative health databases are conducive for population-level research into emergency intra-abdominal surgery. Previous studies have shown an overall in-hospital mortality of 77 per 1000 emergency episodes and demonstrated a survival advantage for patients treated by high volume surgical teams [8].

An increasing number of elderly patients undergo emergency abdominal surgery which reflects demographic change, longer life expectancy, and greater acceptance of emergency operative management in older people [9]. Evaluations of outcomes from emergency surgery for older patients, and the consent process for such procedures, often focus on the ability to prolong life instead of describing potential impacts on function and ability for independent living [7, 10]. A comprehensive understanding of not just survival, but also of the flow of older patients through hospital services is required to ensure that healthcare systems meet the needs of older people. Older survivors of intra-abdominal procedures may experience reduced independence, have different rehabilitation needs and a greater risk of requiring long-term residential care [2]. Healthcare systems must plan for these aspects to achieve best outcomes and avoid unwanted adverse impacts on provision of other hospital services.

The aim of this study was to investigate the discharge outcomes among elderly patients who were admitted to an acute hospital and received emergency abdominal surgery as the primary procedure during their hospital stay. The primary objective was to determine differences in abdominal surgical rates by sex and age groups nationally and by county of residence. A secondary objective was to analyse patient flow to identify relationships between admission sources and discharge destinations. We also wished to determine the extent to which nursing home capacity at county level influences the discharge rate to this destination and post-surgery length of stay.

This population-level study has quantified outcomes including in-hospital mortality, discharge destination and length of stay for patients aged over 65 years undergoing emergency abdominal surgery in Irish hospitals during 2014–2018. The overall in-hospital mortality rate for patients over 65 was 130 per 1000 and increased to 184 per 1000 for patients over 80 years. A mortality rate of 77 per 1000 episodes in a population aged 16 and over has previously been reported [8]. This elevated mortality compares favourably with the first UK NELA report that demonstrated a mortality rate of 244 per 1000 in patients aged 80 or over [5]. We observe an unexplained variation in the proportion of male and female patients of similar age undergoing the procedure and demonstrate an increased need for post-operative nursing home support in this cohort of older patients.

The findings of this study are important in designing a health system that meets the in-hospital, rehabilitation and placement needs of older patients, and are relevant for assisting patients and their families to better understand the risks associated with this type of surgery including the in-hospital mortality as well as the higher risk of post-operative dependency in surviving patients.

The rates of patients undergoing these procedures increase with age up to the age of 90 years, and increases in morbidity and mortality by age are also observed. Previous research has been conflicting with regards to the influence of age on mortality following emergency surgery. In older reports, chronological age is reported to be an independent risk factor for mortality, with mortality reported to increase by approximately 4% for each 10 years of additional age [5]. More recent studies, adjusting for pre-operative morbidity as captured by the ASA classification system and various frailty scores have found that increasing morbidity and frailty, as opposed to simply chronological age, are the independent risk factors [17, 18]. For example, in a series of 220 patients, higher frailty index was associated with in-hospital complications (OR = 2.13; 95% CI; 1.09–4.16; p = 0.02) and major complications (OR = 3.87; 95% CI: 1.69–8.84; p < 0.01) [17]. Although frailty measures do not replace clinical judgement in the assessment of patients who will benefit from surgical intervention, they may provide a valuable support in decision-making.

The rate of emergency abdominal surgery among men aged over 65 years is higher than among women (Fig. 1). This variation cannot be explained by variables in this dataset although gender differences in the presentation of conditions including colorectal cancer have previously been identified [19]. Late presentation of conditions that could otherwise be treated electively might contribute to the observed difference. Previous research has shown that women have better outcomes after abdominal surgery [4, 20], suggesting the incidence of salvage surgery may be higher in men. Differences in rates of intervention by gender have been previously identified; men are 1.8 times more likely to undergo surgery for an intact abnormal aortic aneurysm than women [21] and 3.3 times more likely to be offered cardiac surgery [22]. Importantly, our dataset does not enable identification of patients who were considered for, but who refused or were denied surgery. Gender differences were also present in this cohort with male patients being older, having a higher CCI and more frequently a cancer diagnosis, although no statistically significant gender difference was found in admission source and length of stay. Female patients were more likely to be discharged to nursing home (22.7% vs 19.9%; p = 0.02).

The source of admission is highly influential on the discharge destination. Patients aged over 65 who require emergency surgery and were admitted from a nursing home had more than an 80% incidence of also being discharged to a nursing home and an in-hospital mortality of 18%, compared to rates of 20 and 13% respectively for patients admitted to hospital from home. The initial reason for admission to the nursing home is also relevant. For example, pre-existing dementia influences surgical outcomes: patients with dementia have a higher mortality rate than patients without cognitive impairment [23].

In addition to obvious fiscal consequences, discharge to a nursing home suggests a significant deterioration in levels of independence and, likely, quality of life after emergency abdominal surgery. Validated assessments of quality of life changes after these procedures are challenging due to the emergency nature of their presentation. The rapid deterioration in clinical conditions makes it difficult to make baseline assessment without bias related to recall and non-response.

For patients admitted from home or from another hospital, discharge to a nursing home (19.3%) was a more common outcome than mortality (12.8%) and may be important for patients and their families although current consent practices focus primarily on mortality risk. This would imply that the odds for not being discharged to nursing home or death is 4.2 for patients aged 65–69, reducing to 1 (i.e. a 50dl:50dl chance of returning home) for the over-80 age group. For that reason, morbidity and the ability to live at home are important factors for patients and their family members to consider prior to undergoing emergency surgery. Discharge to a nursing home may happen for a number of reasons: it may be the patient’s usual residence, it may be needed for a short or long period of rehabilitation, or the patient may have become incapable of independent living as a result of their illness. The excess post-operative LOS associated with nursing home discharge (33.8 vs 22.7 days) may reflect more severe illnesses among patients discharged to nursing homes or could indicate that patients are fit to leave hospital but have no access to the step-down nursing home place that they require. Relatively long post-operative hospitalization is observed in our population, a factor that has been associated with reduced function [24]. The UK NELA reports a median post-operative LOS of 11 days but lacks description of discharge destination and includes all ages [5]. In contrast, our study which included only patients older than 65 years observed a mean post-operative LOS of 22 days. Patients who were admitted from home and discharged to a nursing home had a LOS 15.5 days longer than patients discharged home. There was a relationship between longer post-operative LOS and lower nursing home capacity in the patient’s county of residence, although this was not significant (p = 0.08). This may suggest some of the prolongation in LOS results from delay in discharge to nursing home facilities.

There are a number of limitations to this study. NQAIS is based on an administrative dataset and hospital episodes were extracted using primary procedure codes so the quality of clinical record keeping and the accuracy of coding performed at each hospital site is a key limitation. There is no unique patient identifier so prior procedures and patients transferred to other hospitals and having subsequent complications are not included in the dataset. A further limitation in this cohort is the lack of a frailty score in the dataset. The nursing home data was retrieved from the HIQA website, which is responsible for the regulation of all nursing homes in the Republic of Ireland, however it may be missing some smaller private entities. Despite these limitations, this dataset includes every patient treated in a publically funded hospital over the 5-year period, representing the single largest dataset on this population currently available.

The rate of patients undergoing emergency abdominal surgery increases with age, as does mortality. Patients aged 65–69 years undergoing emergency abdominal surgery are 4 times more likely to be discharged home or to another hospital than to a nursing home or to die but This reduces to a 50dl:50dl chance for patients over 80. Patients discharged to a nursing home experience longer LOS. This may partly be explained by nursing home capacity in the patient’s county of residence. This study provides important information to support a better process of informed consent for patients undergoing emergency abdominal surgery and help to improve the planning for a system of care that better meets the needs of older patients who present with an intra-abdominal emergency.