Progress in frailty assessment in the treatment of patients with chronic obstructive pulmonary disease

Wen Zhou, Hong-Hua Guo, Hai-Xia He, Cai-Hong Zhang✉, Jing Yang

1. International School of Nursing,Hainan Medical University,Haikou 571199,China

2. Hainan Provincial People′s Hospital,Haikou 570311,China

Keywords:Chronic obstructive pulmonary disease Frailty Pulmonary rehabilitation Nutritional support

ABSTRACT This paper reviews the asthenia´s occurrence status,adverse outcomes and assessment tools of patients with chronic obstructive pulmonary disease,as well as safety management strategies such as preventing or improving pulmonary rehabilitation and nutritional therapy in patients with asthenia´s.It can provide reference for clinical nurses or researchers to find or develop assessment tool asthenia suitable for domestic patients with chronic obstructive pulmonary disease and set down intervention measurements.

As the population ages and continues to be exposed to COPD risk factors, the medical burden of COPD is expected to continue to increase over the coming decades[1].COPD is a common,preventable disease characterized by persistent respiratory symptoms and limited ventilation.COPD is usually progressive and is associated with increased chronic inflammatory responses in the airways and lungs to harmful particles or gases[2].COPD is the leading chronic respiratory disease,which greatly limits patients' physical functioning and reduces their quality of life.Currently,COPD is the third leading cause of death in the world,increasing the medical and economic burden[3,4]and has become one of the public health issues of worldwide concern.Frailty is an important geriatric syndrome,which is a non-specific state caused by increased vulnerability and decreased anti-stress ability due to aging and decreased physiological reserve[5].When exposed to stressors,frail people are more likely to suffer multiple serious consequences,such as falls, hospitalization,even disability and death[6].On the one hand,frailty is an independent risk factor for exacerbation and progression of COPD patients;on the other hand,COPD patients are also more prone to frailty [7].A recent metaanalysis[8]showed that the risk of weakness associated with COPD patients was twice that of non-COPD patients,leading to cop-D patients being more likely to be hospitalized[9],disabled[10],death [10]and other adverse clinical outcomes.This paper reviews the current status and adverse outcomes of weakness in PATIENTS with COPD,assessment tools,and strategies for pulmonary rehabilitation and nutritional therapy to prevent or improve weakness in patients with COPD,so as to provide references for clinical work.

1. Current status and adverse outcomes of weakness in COPD patients

1.1 Frailty and readmission

In a prospective study conducted by Bernabeu-Mora et al.[9]in 2017,the Edmonton Frailty Scale was used to evaluate 102 hospitalized patients with acute exacerbation chronic obstructive pulmonary disease(AECOPD),and it was found that 21.7% were non-frailty patients,25% were mildly frailty patients,27.8%were moderately frailty patients,and 66.7% were severely frailty patients.It is obvious that patients with AECOPD have significant weakness problems,and follow-up of hospitalized PATIENTS with AECOPD within 90 days after discharge showed that patients with severe weakness in COPD were more likely to be readmitted(45%vs28%) than non-weak patients with COPD,and the frequency of readmission was 5 times higher than that of normal patients.After adjusting for age and related disease in the final multivariable model,severe weakness remained an independent risk factor for readmission in COPD patients within 90 days.Thus, there was a close relationship between frailty and readmission of COPD patients.In addition, Ehsani et al.[11]also discussed the influence of frailty on readmission of AECOPD inpatients,and the results showed that frailty is an important influencing factor for readmission of AECOPD patients,which can effectively predict the risk of readmission.Therefore, it is particularly necessary to take effective measures to intervene and reduce the early admission rate of patients with frailty.

Similarly,Chinese scholar Wang Lu et al.[12]conducted a prospective study on The readmission of COPD patients,using The Clinical Frailty Scale(CFS)to evaluate The Frailty of 117 AECOPD patients,and followed up all AECOPD patients for 3 months.The results showed that the recurrence rate of AECOPD hospitalization within 3 months was 9.4% in the non-frailty group and 84.9% in the frailty group.In addition,the study found that the number of comorbidities( 4)and drug varieties(＞5)in the frailty group were more than those in the non-frailty group.Readmission rate of the weak group was obviously higher than that of previous studies, may be different from previous research weak weak group and assessment tools,not rational drug use and so on, we should pay attention to the medical staff,for elderly patients with weak,the doctor should be individualized treatment,rational drug use, as far as possible to reduce drug kinds and amount[13].

1.2 Frailty and acceptance of disease

Acceptance of disease is one of the most important stages for patients to adapt to the disease.It helps patients to better and faster adapt to the living conditions of the new disease,thus improving the physical and mental health of patients with chronic diseases.There is a close relationship between frailty and acceptance of the disease.Uchmanowicz et al.[14]used the Polish version of "Acceptance Disease Scale" and "Tilburg frailty Index (TFI)" scale for the first time to study the frailty status of 102 elderly AECOPD patients and its impact on acceptance disease.The study showed[14]that the frailty prevalence rate of COPD patients was 75.5%,and the average acceptance level of disease was only 20.6.Compared with other chronic diseases,elderly COPD patients with delayed disease are more likely to experience weakness and significantly lower acceptance of the disease.Domestic scholar Li Huiping[15]selected 87 hospitalized PATIENTS with COPD and conducted a survey of COPD patients using TFI and disease acceptance Scale(AIS).It was found that 74.7% of COPD patients had weakness,and the overall acceptance level of disease was only 20.6.The reason was that TFI had a higher weight in frailty score at the physical and social levels.Thus,the degree of frailty was negatively correlated with the degree of disease acceptance.At present,there are few relevant studies on the influence of the frailness of elderly COPD patients on the disease acceptance.In future studies,accurate assessment and effective intervention of the frailness of elderly COPD patients are still needed to improve the acceptance of COPD patients to the disease,so that patients can achieve better health outcomes.

1.3 Weakness and death

Lahousse et al.[16]conducted a prospective study of 2,142 elderly people living in the community using Fried debilitating phenotype(FFP)to evaluate 402 patients with COPD and 1740 patients without COPD,and the results showed that COPD patients were more likely to develop weakness than non-COPD patients.In addition, during an average of 805 days of follow-up among study subjects,the mortality rate was nearly three times higher in patients with debilitating COPD than in non-debilitating patients without COPD.It is clear that weakness is an independent predictor of increased risk of death in COPD patients.In addition,Galizia et al.[17]conducted a cross-sectional study.Starting from 1992,the FSS was used to follow up 489 patients with COPD and 799 non-COPD patients for 12 years,and it was found that the frailty rate of the non-COPD group and COPD group was 36.8% and 48.9%,and the mortality rate of the non-COPD group and COPD group was 48.1%and 60.7%, respectively.In addition,multi-factor analysis showed that frailty score could predict long-term mortality.For non-COPD patients,frailty increased mortality by 34% and increased mortality by 80%.Thus,the clinical frailty score was a significant predictor of mortality in non-COPD patients and even better for COPD patients.Thus,clinical frailty was used as a new prognostic factor to determine the high mortality of patients with COPD.

2. Methods for the assessment of weakness in COPD patients

2.1 Prediction Model

In recent years,frailty has become a hot topic in the field of gerontology.However,the definition of frailty is still controversial in the international community,and there is only a consensus on the conceptual framework of frailty.The most widely used phenotypic models are the attenuated phenotypic model and the deficiency accumulation model.

2.1.1 Phenotypic model of weakness

FFP is the most commonly used assessment tool for evaluating the weakness degree of COPD patients,which was proposed by Fried et al.[18]in 2001,including 5 indicators,such as slow walking speed,low grip strength,low physical activity,fatigue and unexplained weight loss,which meet 3 or more of the 5 indicators as weakness.If 1～2 indexes are met,it is the early stage of frailty;None of them were consistent with nonenfeebleness.Most of the studies on the interaction between COPD and frailty are evaluated by FFP,which has become the most extensive and classic assessment tool for the frailty measurement of COPD patients,and has been used to predict the mortality rate and adverse clinical outcome of elderly population living in the community[19].However,the frailty phenotype model only evaluates the frailty from the physiological level, and does not involve the psychological,cognitive and social aspects of COPD patients.Therefore, FFP assessment tools have certain deficiencies.

2.1.2 Weak loss accumulation model

2005,Rockwood[20]weak cumulative damage index model(Frailty index, FI),FI is in Canada health and aging (CSHA)developed on the basis of,is a kind of multi-dimensional breakdowns,measuring tools,involved the accumulation of 20～70 age related health indicators,including complications,symptoms,disease,disabili ty,or any defects of health.The FI model can use clinical data collected from medical records to assess frailty and thus intervene in elderly people who have been identified as frail.However,the time-consuming calculation of FI makes it difficult for FI to be widely used in clinical practice.On this basis,Chinese scholars[21]have developed a debilitating index assessment tool with 5 dimensions,including symptoms,daily activities,diseases,psychological problems and simple intelligence and spirit scale,with a total of 35 items,taking into account the effectiveness and stability,which makes up for the deficiency of FFP phenotype model in the evaluation of patients'psychological,cognitive and social aspects.

2.2 Assessment Tools

At present,a variety of frailty assessment tools have been developed,including the frailty assessment based solely on physiology,as well as the comprehensive frailty assessment based on physiology,cognition and society.However,these frailty assessment tools are almost based on the frailty phenotype and frailty index of Fried[7,22].Limpawattana et al.[6]conducted a cross-sectional survey on the frailty of COPD patients with the use of the FRAIL scale,showing that the prevalence rate of frailty in COPD patients was 6.6%.All the scale indicators of FRAIL patients were higher than those of non-frail patients,and fatigue was the main factor of frailty in these groups.What effective measures should be taken to benefit patients with COPD due to fatigue is the key question we need to explore in the future.Chinese scholar Tian Gang et al.[23]used the FRAIL scale to evaluate the frailty of 378 COPD patients who were hospitalized in outpatient clinic and ward, and found that the prevalence rate of frailty was 44.7%.Chen Pei et al.[24],in a crosssectional survey, used the FRAIL scale to evaluate the frailty of 363 patients with stable COPD,and found that the prevalence of frailty was 8.3% and 27.8% respectively.Therefore,while while it is simple and easy to use,it can be used to quickly screen people at high risk for COPD weakness,which has been recognized by domestic and foreign experts [6,25].However, studies on the FRAIL assessment of hospitalized patients using the FRAIL scale are still limited.

Kusunose et al.[26]prospectively studied 79 Japanese outpatient patients with stable COPD using the Kihon Checklist(KCL)for frailness assessment,and found that 34% of patients with COPD were in the early stage of frailness,and 21.5% of patients with COPD were in the weak stage.In addition, a systematic review of KCL showed that[27]KCL was predictive of dependency and mortality in the elderly in the community,but the value of KCL in assessing the weakness of hospitalized COPD patients remains to be further explored.

A study used TFI scale to investigate the frailty of 102 AECOPD inpatients,and the results showed that the incidence of frailty in COPD patients was 75.5%,significantly higher than that in other chronic diseases [14].Chinese scholar Li Huiping et al.[15]also completed the reliability and validity study of this scale, and used TFI scale to evaluate the frailty of COPD patients,with a frailty prevalence rate of 74.7%.It can be seen that the Sinicized TFI scale has good applicability in COPD patients in China,which can be further verified by increasing the sample size and popularating it in outpatient clinics or communities in the future.

Weak at present,in view of the patients with COPD assessment tool, weak on COPD patients the best assessment tools are still controversial,some weak assessment tool is suitable for the screening of the health of the community people and other tools are applicable to evaluate the clinic or hospital patients,it is necessary for patients with COPD debilitating assessment tool for further study,it should be for a specific group of COPD,to establish a more effective assessment tools,thus improve the screening and identification of the effectiveness of the different course of patients with COPD,guide the health care workers with personalized treatment options.

3. Prevention or improvement strategies for weakness in COPD patients

Studies have found[28]that pulmonary rehabilitation can reverse COPD patients with combined weakness who respond well to treatment. Similarly,many of the factors associated with frailty can be ameliorated through preventive and supportive treatments,such as exercise and nutritional interventions.Therefore, intervention strategies are particularly important for patients with debilitating COPD.In 2012,the American and European geriatrician consensus[29]clearly stated that all the elderly 70 years old should be screened for frailty, especially those with heart failure,kidney failure,diabetes and chronic diseases,who can benefit from early screening and intervention for frailty.Pulmonary rehabilitation and nutritional intervention are currently the most effective measures to prevent or improve the weakness of COPD patients.

3.1 Pulmonary rehabilitation

According to the 2017 COPD Global Initiative report,pulmonary rehabilitation is the most effective therapeutic intervention to reduce dyspnea and improve physical condition and quality of life[30].Maddocks et al.[28]perform an 8-week outpatient exercise and multidisciplinary education programme for COPD patients, including supervised training twice a week and at least one home-based training session,in accordance with the British Thoracic Society's Pulmonary Rehabilitation Quality Standards[31].The exercise training followed a personalized and asymptotic nature.The initial walking speed prescription was based on the incremental shuttle walking test(ISWT),which predicted 80% of peak oxygen consumption,while the initial endurance cycling was set for 10min of continuous load training.The lower extremity resistance training consisted of two groups of 10 seated leg compressions, repeated up to once at 60%of the initial training load,and sitting to standing, knee extension,hip flexion, and hip abduction exercises.Upper body resistance training includes bicep curls, shoulder pressure and upright rowing with free weights.Education is provided by a multidisciplinary team[28].The results of the study showed that among 115 patients with frailty who had completed pulmonary rehabilitation, 61.3% of the COPD patients at the early stage of frailty no longer met the frailty criteria after completing pulmonary rehabilitation,and only 10% of them met the frailty criteria.The physical, psychological and overall health conditions of the patients were improved,which had positive therapeutic significance for the patients with frailty.In addition,Chinese scholar Liu Hong[32]conducted 12-week family pulmonary rehabilitation and telephone follow-up of 50 COPD patients with stable COPD and found that the weakness score and physical activity ability of COPD patients after intervention were significantly higher than before intervention,indicating that family pulmonary rehabilitation can improve or delay the weakness of COPD patients with stable COPD,which is worthy of promotion.Although lowintensity training regimen was adopted in this study for patients with severe weakness, exercise compliance of COPD patients was still insufficient.Therefore,compliance of pulmonary rehabilitation exercise needs to be paid attention to.However, there is still a lack of research in this area,and in-depth research on how to effectively improve pulmonary rehabilitation exercise compliance of COPD patients should be conducted in the future.

3.2 Nutritional intervention

Studies have shown that malnutrition is one of the factors affecting the occurrence of frailty,and the improvement of nutritional status can effectively improve the frailty,thus delaying the physical function of frailty[33].Studies have shown that continuous nutrition supplementation has no significant effect on lung function,respiratory muscle strength and functional exercise ability of patients with stable COPD[32].If intervention is not timely,personal nutrition supplementation may not be able to reverse the decline in muscle strength and function [34].Thus,the importance of nutritional interventions in slowing down the debilitating process of COPD patients,and effective nutritional interventions still need to be further studied to confirm.

4. Outlook

At present,foreign researchers have conducted a large number of studies on the status quo and influencing factors of the weakness of COPD patients,but no consensus has been reached on the standard assessment tools for the weakness of COPD patients,and no standardized intervention studies have been proposed.In China,the research on combined weakness of COPD patients is still at the exploratory stage,and there is still a lack of cross-sectional investigation on the combined weakness of large sample of COPD patients in various regions of the country.Moreover, the assessment and intervention of the combined weakness of COPD patients, a special group with an increasing number of patients,should become the focus of treatment.However,currently,there are inconsistencies in the frailty assessment tools for COPD patients,resulting in a large difference in the frailty prevalence rate among COPD patients.It is suggested that researchers develop frailty assessment tools applicable to COPD patients in China in the future,and develop operable and targeted intervention measures,so as to prevent or delay the frailty of COPD patients,reduce the occurrence of adverse outcomes, and thus improve the health outcomes.

Author's Contribution

Zhou Wen, Guo Honghua and He Haixia conceived and designed the article. Zhou Wen and Yang Jing collected and collated the data.Zhou Wen to write papers;Zhou Wen, Zhang Caihong and Guo Honghua revised the paper. Zhang Caihong and Yang Jing revise the article into English;Guo Honghua and He Haixia are responsible for the quality control and proofreading of articles;Zhang Caihong is responsible for the overall supervision and management of the article.

There is no conflict of interest in this article.