Hospital Careful Hand Feeding Program Reduced Feeding Tube Use in Patients with Advanced Dementia

OBJECTIVES

Tube feeding is prevalent among patients with advanced dementia despite empirical data that suggest its lack of benefit. To provide an alternative to tube feeding for end-of-life patients, a careful hand feeding program was launched in a Hong Kong geriatric convalescent hospital in February 2017. We aim to compare the rates of feeding tube insertion before and after program implementation and determine risk factors for feeding tube insertion. For patients on careful hand feeding, we evaluated their sustainability on oral feeding and the rates of hospital readmissions compared with tube feeding patients over the next 12 months.

DESIGN

Retrospective cohort study.

SETTING AND PARTICIPANTS

Advanced dementia patients ≥60 years with indication for tube feeding due to feeding problems admitted from January 2015-June 2019.

METHODS

Data was collected on demographic and clinical variables, initial feeding mode (careful hand feeding vs. tube feeding), subsequent feeding mode changes, and hospital admissions over the next 12 months. Rates of feeding tube insertion, sustainability on oral feeding, and hospital readmissions were compared using Chi-square test. Risk factors for feeding tube insertion were assessed using logistic regression models.

RESULTS

Among 616 advanced dementia patients admitted with feeding problems, feeding tube insertion rate declined significantly after careful hand feeding program implementation (72% vs 51% p<.001). Independent risk factors for feeding tube insertion were admission prior to program implementation, presence of dysphagia alone, dysphagia combined with poor intake, and lack of advance care planning. Among patients on careful hand feeding, 91% were sustained on oral feeding over the next twelve months and did not differ significantly before or after careful hand feeding program implementation (p=.67). There was no significant difference in hospital readmission rates between careful hand feeding patients and tube feeding patients before (83% vs 86%, p=.55) and after careful hand feeding program implementation (87% vs 85%, p=.63).

CONCLUSIONS AND IMPLICATIONS

A hospital careful hand feeding program significantly reduced the feeding tube insertion rate among advanced dementia patients with feeding problems. The vast majority of patients on careful hand feeding were sustained on oral feeding over the next 12 months but their rate of hospital readmissions remained similarly high after program implementation.

Effectiveness of Partially Hydrolyzed Guar Gum in Reducing Constipation in Long Term Care Facility Residents: A Randomized Single-Blinded Placebo-Controlled Trial

OBJECTIVES

To assess the effectiveness of partially hydrolyzed guar gum (PHGG) in improving constipation and reducing the use of laxatives among long term care facility (LTCF) residents.

DESIGN

A single-center, prospective, randomized, placebo-controlled, single-blinded parallel-group trial from September 2021 to November 2021.

SETTING

Four LTCF in Hong Kong.

PARTICIPANTS

Fifty-two LTCF residents with chronic constipation (mean age: 83.9±7.6 years, male 38%).

INTERVENTION

5g PHGG mixed with 200ml water per day for 4 weeks was given to intervention group participants. Control group received 200ml water for 4 weeks. Participants continued their usual as-needed laxative (lactulose, senna or dulcolax) on their own initiative.

MEASUREMENTS

Baseline measurements included age, gender, Charlson comorbidity index, Roackwood's Clinical Frailty Scale, body mass index and daily dietary fiber intake. Outcome measures were fecal characteristics assessed by Bristol Stool Form Scale, bowel opening frequency and laxative use frequency at baseline, first, second, third and fourth week of trial. Adverse events were measured. The study was registered on ClinicalTrial.gov; identifier: NCT05037565.

RESULTS

There was no significant difference in bowel frequency and stool characteristics between the treatment group and control group. However, there was a significantly lower frequency of lactulose, senna, and total laxative use in the treatment group compared with controls in the third and fourth week. There was no significant difference in adverse effects between the two groups.

CONCLUSION

This study showed that daily dietary fibre supplementation by using PHGG for 4 weeks in LTCF residents results in significantly less laxative use than placebo. It may be an effective way to reduce laxative dependence among older people living in LTCFs.

Reduced Pneumonia Risk in Advanced Dementia Patients on Careful Hand Feeding Compared With Nasogastric Tube Feeding

OBJECTIVES

To compare survival and pneumonia risk among hospitalized patients with advanced dementia on nasogastric tube feeding (NGF) vs careful hand feeding (CHF) and to examine outcomes by feeding problem type.

DESIGN

Retrospective cohort study.

SETTING AND PARTICIPANTS

Advanced dementia patients aged ≥60 years with indication for tube feeding admitted to 2 geriatric convalescent hospitals between January 1, 2015, and June 30, 2019.

METHODS

Comparison on the effect of NGF and CHF on survival and pneumonia risk using Kaplan Meier survival analysis and Cox proportional hazards models.

RESULTS

Of the 764 patients (mean age 89 years, 61% female, 74% residential care home residents), 464 (61%) were initiated on NGF and 300 (39%) on CHF. The primary feeding problem types were dysphagia (50%), behavioral feeding problem (33%), or both (17%). There was no difference in 1-year survival rate between NGF and CHF groups (36% vs 37%, P = .71) and survival did not differ by feeding problem type. Nasogastric tube feeding was not a significant predictor for survival (adjusted hazard ratio 1.15, 95% CI 0.94-1.39). Among 577 (76%) patients who survived to discharge, pneumonia rates were lower in the CHF group (48% vs 60%, P = .004). After adjusting for cofounders, NGF was a significant risk factor for pneumonia (adjusted hazard ratio 1.41, 95% CI 1.08-1.85). In subgroup analyses, NGF was associated with increased pneumonia risk for patients with both dysphagia and behavioral feeding problem (P = .01) but not in patients with behavioral feeding problem alone (P = .24) or dysphagia alone (P = .30).

CONCLUSIONS AND IMPLICATIONS

For advanced dementia patients with feeding problems, there is no difference in survival between NGF and CHF. However, NGF is associated with a higher pneumonia risk, particularly for patients with both dysphagia and behavioral feeding problem. Further research on how the feeding problem type impacts pneumonia risk for patients on NGF is needed.

Natural clinical course of progressive supranuclear palsy in Chinese patients in Hong Kong

INTRODUCTION

Progressive supranuclear palsy (PSP) is a common type of atypical parkinsonism. To the best of our knowledge, there has been no study of its natural clinical course among Chinese patients.

METHODS

This retrospective study included 21 patients with PSP who had radiological evidence of midbrain atrophy (confirmed by magnetic resonance imaging) from the geriatrics clinics of Queen Mary Hospital and Tuen Mun Hospital. Clinical information was retrieved from clinical records, including age at onset, age at presentation, age at death, duration of symptoms, level of education, sex, presenting scores on Cantonese version of Mini-Mental State Examination, clinical symptoms, and history of levodopa or dopamine agonist intake and response. Clinical symptoms were clustered into the following categories and the dates of development of these symptoms were determined: motor symptoms, bulbar symptoms, cognitive symptoms, and others.

RESULTS

Motor symptoms developed early in the clinical course of disease. Cox proportional hazards modelling showed that the number of episodes of pneumonia, time to vertical gaze palsy, and presence of pneumonia were predictive of mortality. Apathy, dysphagia, pneumonia, caregiver stress, and pressure injuries were predictive of mortality when analysed as time-dependent covariates. There was a significant negative correlation between the age at presentation and time to mortality from presentation (Pearson correlation=-0.54, P=0.04). Approximately 40% of caregivers complained of stress during the clinical course of disease.

CONCLUSION

Important clinical milestones, including the development of dysphagia, vertical gaze palsy, significant caregiver stress, pressure injuries, and pneumonia, may guide advanced care planning for patients with PSP.

Effectiveness of a Day Rehabilitation Program in Improving Functional Outcome and Reducing Mortality and Readmission of Elderly Patients With Fragility Hip Fractures

Introduction:

The incidence of hip fracture is projected to increase in the next 25 years as the world population ages. Hip fracture is often associated with subsequent readmission and mortality. Nevertheless, elderly patients often may not achieve the same level of functional ability as prior to their injury. Several studies have shown that close collaboration between orthopedic surgeons and geriatricians can improve such outcomes and Geriatric Day Hospital (GDH) is one of the examples of collaboration to improve such outcomes. The aim of this descriptive retrospective study is to review the effectiveness of the day rehabilitation program provided by a GDH on functional outcomes, mortality, and readmission rate, among a sample of elderly patients with hip fracture.

Methods:

The medical records of patients from January 1, 2009, to December 31, 2012, were collected and evaluated. Demographic data of the patients and Charlson Comorbidity Index were collected. The Barthel Index, Elderly Mobility Scale, and Mini-Mental State Examination were measured on admission and at discharge of the patients to evaluate both physical and cognitive functions.

Results:

The results showed that the majority of patients benefited from rehabilitation in the GDH. The 12-month mortality rate of patients taking full-course rehabilitation in the GDH was improved. The age of patient was the most important factor influencing the rehabilitation outcomes. Gender was the only risk factor for 12-month mortality and 6-month readmission.

Discussion:

Since patients were selected to attend GDH, there was a bias during the selection of patients. Furthermore, it was difficult to compare patients attended GDH with patients who did not because outcomes of the latter were difficult to be recorded.

Conclusions:

Our study shows that postoperative geriatric hip fracture patients definitely can benefit from rehabilitation service offered by GDH in terms of functional and cognitive outcomes.

End-of-life care for advanced dementia patients in residential care home-a Hong Kong perspective

Dementia will become more common as the population ages. Advanced dementia should be considered as a terminal illnesses and end-of-life (EOL) care is very much needed for this disease group. Currently, the EOL services provided to this vulnerable group in Hong Kong, especially those living in residential care homes, is limited. The usual practice of residential care homes is to send older residents with advanced dementia to acute hospitals when they are sick, irrespective of their wish, premorbid status, diagnoses and prognosis. This may not accord with what the patients perceive to be a "good death". There are many barriers for older people to die in place, both at home and at the residential care home. In the community, to enhance EOL care to residential care home for the elderly (RCHE) residents, pilot EOL program had been carried out by some Community Geriatric Assessment Teams. Since 2015, the Hospital Authority funded program "Enhance Community Geriatric Assessment Team Support to End-of-life Patients in Residential Care Homes for the Elderly" has been started. In the program, advance care planning (ACP), Do Not Attempt Cardiopulmonary Resuscitation (DNACPR) (non-hospitalized) order will be established and the program will be expected to cover all clusters in Hong Kong by 2018/2019. In hospital setting, EOL clinical plan and EOL ward in geriatric step-down hospitals may be able to improve the quality of death of older patients. In Sep 2015, the Hospital Authority Guidelines on Life-Sustaining Treatment in the Terminally Ill was updated. Amongst other key EOL issues, careful (comfort) hand feeding was mentioned in the guideline. Other new developments include the possible establishment of enduring power of attorney for health care decision and enhancement of careful hand feeding amongst advanced dementia patients in RCHEs.

Prevention in primary care is better than cure: The Hong Kong Reference Framework for Preventive Care for Older Adults--translating evidence into practice

An ageing population is posing a great challenge to Hong Kong. Maintaining health and functional independence among older adults is of utmost importance, and requires the collaborative efforts of multiple health care disciplines from both the private and public sectors. The Reference Framework for Preventive Care for Older Adults, developed by the Task Force on Conceptual Model and Preventive Protocols under the auspices of the Working Group on Primary Care, aims to enhance primary care for this population group. The reference framework emphasises a comprehensive, integrated, and collaborative approach that involves providers of primary care from multiple disciplines. In addition to internet-based information, helpful tools in the form of summary charts and Cue Cards are also produced to facilitate incorporation of recommendations by primary care providers into their daily practice. It is anticipated that wide adoption of the reference framework will contribute to improving older adults' health in our community.

Effectiveness of a discharge planning and community support programme in preventing readmission of high-risk older patients

OBJECTIVE

To examine the effectiveness of Integrated Care and Discharge Support for elderly patients in reducing accident and emergency department attendance, acute hospital admissions, and hospital bed days after discharge. Factors that compromise its effectiveness were investigated and cost analysis was performed.

DESIGN

Cohort prospective study.

SETTING

Integrated Care and Discharge Support for elderly patients in Hong Kong West Cluster.

PARTICIPANTS

Home-dwelling patients recruited between April 2012 and March 2013 into Integrated Care and Discharge Support for elderly patients in Hong Kong West Cluster.

RESULTS

A total of 1090 older patients were studied. The Integrated Care and Discharge Support for elderly patients programme reduced accident and emergency department attendance by 40% (P<0.001), acute hospital admissions by 47% (P<0.001), and hospital bed days by 31% (P<0.001) at 6 months after implementation. Improvements in Barthel Index 20 (P<0.001) and Modified Functional Ambulation Category scale (P<0.001) were observed. Of the patients, 85 (7.8%) died within 6 months of initiation of the programme. Only 26 (2.4%) older patients required institutionalisation in residential care homes within 6 months after the programme. Increasing age (P=0.025) and high Charlson Comorbidity Index score (P=0.001) were positive predictors for accident and emergency department attendance. A high albumin level (P=0.001) and living alone (P=0.033) were negative predictors for accident and emergency department attendance. Of the patients, 310 (28.4%) had no reduction in bed days after the programme. Increasing age (P=0.025) and number of medications (P=0.003) were positive predictors for no reduction in bed days; while higher haemoglobin level (P=0.034) was a negative predictor. There was a potential annual cost-saving of HK$22.5 million (approximately US$2.9 million).

CONCLUSION

The Integrated Care and Discharge Support for elderly patients programme reduced accident and emergency department attendance, acute hospital admissions and hospital bed days, and was potentially cost-saving. Age, Charlson Comorbidity Index, albumin level, and living alone were factors associated with accident and emergency department attendance. Age, number of medications, and haemoglobin level were associated with no reduction in bed days. Further study of the cost-effectiveness of such programme is warranted.

Dignified Palliative Long-Term Care: An Interpretive Systemic Framework of End-of-Life Integrated Care Pathway for Terminally Ill Chinese Older Adults

PURPOSE

To critically examine the system dynamics necessary for successfully implementing a novel end-of-life integrated care pathway (EoL-ICP) program in promoting dignity and quality of life among terminally-ill Chinese nursing home residents.

METHODS

Thirty stakeholders were recruited to participate in 4 interpretive-systemic focus groups.

RESULTS

Framework analysis revealed 10 themes, organized into 3 categories, namely, (1) Regulatory Empowerment (interdisciplinary teamwork, resource allocation, culture building, collaborative policy making), (2) Family-Centered Care (continuity of care, family care conference, partnership in care), and (3) Collective Compassion (devotion in care, empathic understanding, compassionate actions).

CONCLUSIONS

These findings highlight the importance of organizational structure, social discourse, and shared meaning in the provision of EoL-ICP in Chinese societies, underscoring the significant triangulation between political, cultural, and spiritual contexts embodied in the experience of dignity.

Mortality and health services utilisation among older people with advanced cognitive impairment living in residential care homes

OBJECTIVES

To study the demography, clinical characteristics, service utilisation, mortality, and predictors of mortality in older residential care home residents with advanced cognitive impairment.

DESIGN

Cohort longitudinal study.

SETTING

Residential care homes for the elderly in Hong Kong West.

PARTICIPANTS

Residents of such homes aged 65 years or more with advanced cognitive impairment.

RESULTS

In all, 312 such residential care home residents (71 men and 241 women) were studied. Their mean age was 88 (standard deviation, 8) years and their mean Barthel Index 20 score was 1.5 (standard deviation, 2.0). In all, 164 (53%) were receiving enteral feeding. Nearly all of them had urinary and bowel incontinence. Apart from Community Geriatric Assessment Team clinics, 119 (38%) of the residents attended other clinics outside their residential care homes. In all, 107 (34%) died within 1 year; those who died within 1 year used significantly more emergency and hospital services (P<0.001), and utilised more services from community care nurses for wound care (P=0.001), enteral feeding tube care (P=0.018), and urinary catheter care (P<0.001). Independent risk factors for 1-year mortality were active pressure sores (P=0.0037), enteral feeding (P=0.008), having a urinary catheter (P=0.0036), and suffering from chronic obstructive pulmonary disease (P=0.011). A history of pneumococcal vaccination was protective with respect to 1-year mortality (P=0.004).

CONCLUSION

Residents of residential care homes for the elderly with advanced cognitive impairment were frail, exhibited multiple co-morbidities and high mortality. They were frequent users of out-patient, emergency, and in-patient services. The development of end-of-life care services in residential care homes for the elderly is an important need for this group of elderly.

Transmission of methicillin-resistant Staphylococcus aureus in the long term care facilities in Hong Kong

Background

The relative contribution of long term care facilities (LTCFs) and hospitals in the transmission of methicillin-resistant Staphylococcus aureus (MRSA) is unknown.

Methods

Concurrent MRSA screening and spa type analysis was performed in LTCFs and their network hospitals to estimate the rate of MRSA acquisition among residents during their stay in LTCFs and hospitals, by colonization pressure and MRSA transmission calculations.

Results

In 40 LTCFs, 436 (21.6%) of 2020 residents were identified as ‘MRSA-positive’. The incidence of MRSA transmission per 1000-colonization-days among the residents during their stay in LTCFs and hospitals were 309 and 113 respectively, while the colonization pressure in LTCFs and hospitals were 210 and 185 per 1000-patient-days respectively. MRSA spa type t1081 was the most commonly isolated linage in both LTCF residents (76/121, 62.8%) and hospitalized patients (51/87, 58.6%), while type t4677 was significantly associated with LTCF residents (24/121, 19.8%) compared with hospitalized patients (3/87, 3.4%) (p < 0.001). This suggested continuous transmission of MRSA t4677 among LTCF residents. Also, an inverse linear relationship between MRSA prevalence in LTCFs and the average living area per LTCF resident was observed (Pearson correlation −0.443, p = 0.004), with the odds of patients acquiring MRSA reduced by a factor of 0.90 for each 10 square feet increase in living area.

Conclusions

Our data suggest that MRSA transmission was more serious in LTCFs than in hospitals. Infection control should be focused on LTCFs in order to reduce the burden of MRSA carriers in healthcare settings.

Evaluation of the learning outcomes of a year-long postgraduate training course in community geriatrics for primary care doctors

There are increasing expectations on primary care doctors to shoulder a bigger share of care for patients with common geriatric problems in the community. This study aims to examine the outcomes of a postgraduate training course in geriatrics for primary care doctors. A questionnaire developed by the research team was sent to the course graduates (years 2001-2007). Ninety-eight replies were received with a response rate of 52.4% (98/187). Difference in the ratings by the respondents before and after taking the course was analyzed using the nonparametric Wilcoxon signed rank test. Most respondents felt more rewarding and had participated more in geriatric care, and the majority had improvement in their communication skills with elderly patients after taking the course. Moreover, the graduates are more confident in diagnosing and managing common geriatric problems, and deciding to which specialty to refer the elderly patients. Of the referrals, there was a significant increase to private geriatricians and a significant reduction to other specialists. The average number of elderly patients seen per day had also increased. However, little change was observed about making nursing home visits, the frequency of which remained low. Many graduates expressed difficulties in conducting nursing home visits.

Financial abuse in a mentally incapacitated old man

A mentally incapacitated 82-year-old man with no relatives was managed by a geriatrician-led multidisciplinary team when medical staff realised he was at risk of being exploited. They initiated a series of protective measures including an emergency guardianship application. The Guardianship Board appointed the Director of Social Welfare as his public guardian. This case illustrates that hospital staff should be alert to potential elder abuse to ensure timely protection of potential victims.

Tuberculin skin test reaction and body mass index in old age home residents in Hong Kong

OBJECTIVES

To study the relationship between body mass index (BMI) and tuberculin skin test (TST) reaction in predicting the development of active tuberculosis (TB).

DESIGN

A follow-up study.

SETTING

Old age homes.

PARTICIPANTS

Three thousand six hundred five residents who took part in a screening program for TB and had two-step TST using two units of the tuberculin PPD-RT23.

MEASUREMENTS

Rate of development of active TB in these residents over an average follow-up period of 2.5+/-1.25 years.

RESULTS

After one-step and two-step testing, 46.3% and 69.6% of residents, respectively, had positive TST reactions (> or =10 mm). Thirty-four residents developed active TB (323 per 100,000 person-years) during follow-up. The only significant risk factors associated with development of active TB were positive TST according to one-step testing (adjusted odds ratio (OR)=2.91, 95% confidence interval (CI)=1.26-6.74) and a BMI less than 18.5 (adjusted OR=3.15, 95% CI=1.45-6.86). Residents with a BMI less than 18.5 and a negative TST also had greater risk of active TB than residents with a BMI greater than 18.5 and negative TST (adjusted OR=4.36, 95% CI=1.04-18.3), whereas those with a positive TST had the highest risk (adjusted OR=10.2, 95% CI=2.63-39.4). Two-step testing increased the sensitivity but reduced the specificity of TST in identifying active TB on follow-up.

CONCLUSION

In the elderly population, interpretation of TST should take into consideration the BMI of the individual. A positive TST according to one-step but not two-step testing was useful in predicting the development of active TB on follow-up.

Prevalence of tuberculous infection and active tuberculosis in old age homes in Hong Kong

OBJECTIVES

To assess the prevalence of tuberculous infection and active tuberculosis (TB) in old age homes in Hong Kong and to determine whether there is institutional transmission in these homes.

DESIGN

Cross-sectional.

SETTING

Old age homes.

PARTICIPANTS

Total of 2,243 residents, representing 84.6% of all residents in 15 old age homes; 1,698 were women, and 545 were men, with an average age of 82.

MEASUREMENTS

All residents had a questionnaire-based interview, medical record review, two-stage tuberculin testing using two units purified protein derivative-RT23, and a chest x-ray. Those with radiological abnormalities had sputum examined for acid-fast bacilli.

RESULTS

The estimated prevalence rate of active TB in this population was 669 per 100,000, significantly higher in men than in women (1,101 per 100,000 vs 530 per 100,000). The proportion with positive tuberculin reactivity (> or =10 mm induration) after two-stage testing was 68.6%, significantly higher in men than in women. There was no evidence of active transmission of disease in these old age homes, with restriction fragment length polymorphism (RFLP) analysis performed on five cases of active pulmonary TB in the home with the highest rate of TB showing unique RFLP patterns.

CONCLUSION

The rate of active TB and TB infection in old age homes in Hong Kong is still high. Because treatment for latent TB carries a high risk for liver dysfunction in this population, clinicians and other healthcare workers need a high index of suspicion and to diagnose and treat this disease as early as possible to prevent transmission.

Prevalence and determinants of positive tuberculin reactions of residents in old age homes in Hong Kong

OBJECTIVE

To determine the prevalence of tuberculous infection and the predictors of positive tuberculin reactivity in old age home residents in Hong Kong.

DESIGN

Cross-sectional study.

METHODS

A questionnaire-interview and review of medical records were carried out, together with measurement of weight and height/arm span and assessment of nutritional status. A one-stage tuberculin skin test (TST) was performed using two units of PPD RT23. An induration > or = 10 mm was considered as positive.

RESULTS

Of 3682 residents (71.7% participation, mean age 82 years) who agreed to undergo a TST, 46.3% had a positive reaction. Factors associated with a significantly higher risk of a positive TST included being male, an ex- or current smoker and having a past history of tuberculosis (TB). Factors associated with reduced positive tuberculin reactivity included older age groups (> 70 years), a history of cancer and chronic obstructive pulmonary disease and low body mass index quartiles.

CONCLUSION

In old age homes, the high prevalence of latent tuberculous infection is responsible for the high rate of active TB due to reactivation. Early diagnosis and treatment are necessary to prevent transmission of disease in these crowded environments with susceptible individuals.

Managing older patients with urinary retention in the Continence Clinic

OBJECTIVE

To evaluate the effectiveness of the Continence Clinic for managing retention of urine in older patients.

DESIGN

Retrospective study.

SETTING

Continence Clinic, Fung Yiu King Hospital, Hong Kong.

SUBJECTS AND METHODS

Case notes of 58 patients seen at the Fung Yiu King Hospital Continence Clinic from October 1997 to September 2001 were reviewed. The patients had retention of urine with post-void residual volume of more than 200 mL, retention of urine requiring catheterization, or had catheters for unknown reasons.

RESULTS

Urodynamic study performed for 22 (38%) patients showed that 12 had detrusor underactivity, six had detrusor hyperactivity with impaired contraction, and four had bladder outlet obstruction. Among the patients who were initially catheterized, the success rate for gradually stopping reliance on urinary catheterization was 84%. The success rate was higher among those who did not undergo urodynamic study than among those who had the study done (95% versus 67%; P=0.03). Reduction in post-void residual volume was observed at the last clinic visits (P<0.0001). Moreover, significant decreases in post-void residual volume were found both for patients who did and did not have urodynamic study.

CONCLUSION

Most of the older patients with urinary retention with or without indwelling catheters were treated successfully in the Continence Clinic by appropriate medical therapy. Urodynamic study can be performed for selected patients when managing urinary retention.