A case report to understand the use of an evidence-based approach of prolonged grief therapy in Chinese culture.

Prolonged grief disorder (PGD) is a new diagnosis that may cause significant functional impairment. Prolonged grief therapy (PGT) is a manualized 16-session intervention, whose efficacy has been demonstrated in studies primarily from Western cultures. The current report aimed to present a case to illustrate the use of PGT in Chinese culture. The client was a bereaved adult suffering from PGD after the death of her mother ten years ago. Additionally, she lost her father three months ago. Questionnaires were completed before and after treatment. In-depth interview was conducted at a 3-month follow-up. The client's scores for grief, functional impairment, grief-related beliefs and avoidance, depression and insomnia all decreased substantially after treatment. The follow-up feedbacks indicated that the beneficial effects of PGT persisted in the client's life. This case report provides preliminary evidence that bereaved people in China could benefit greatly from PGT, with minimal cultural adaptation.

Bereavement, Memorial Attendance, and Mental Health During the COVID-19 Pandemic: Longitudinal Results from the Nurses' Health Study.

BACKGROUND: Mortality increased during the COVID-19 pandemic. Many bereaved individuals were not able to gather to memorialize their loved ones, yet it is unknown if this contributed to worsening mental health. OBJECTIVE: Examine the association of bereavement in the early part of the COVID-19 pandemic with subsequent psychological distress and the role of memorial attendance in reducing psychological distress among the bereaved. DESIGN, SETTINGS, SUBJECTS: In May 2020, 39,564 older females from the Nurses' Health Study II enrolled in a longitudinal COVID-19 substudy (meanage = 65.2 years, SD = 4.5). METHODS: Linear regression analyses estimated associations of bereavement reported between March and October, 2020 with subsequent psychological distress between January and October 2021, adjusting for sociodemographic and prepandemic depression symptoms. Secondary models examined associations between memorial attendance and psychological distress. RESULTS: Bereavement during the early part of the COVID-19 pandemic was associated with higher psychological distress (adjusted ß = 0.21, 95% CI: 0.15, 0.26) assessed over the next year. Among the bereaved, memorial attendance was associated with lower psychological distress (in-person: adjusted ß = -0.41, 95% CI: -0.53, -0.29; online: adjusted ß = -0.24, 95% CI: -0.46, --0.02). CONCLUSION: Attending memorials was associated with lower subsequent psychological distress among bereaved older females.

A Web-Based Therapist Training Tutorial on Prolonged Grief Disorder Therapy: Pre-Post Assessment Study.

BACKGROUND: Prolonged grief disorder (PGD) is a newly recognized mental disorder characterized by pervasive intense grief that persists longer than cultural or social expectations and interferes with functioning. The COVID-19 epidemic has resulted in increased rates of PGD, and few clinicians feel confident in treating this condition. PGD therapy (PGDT) is a simple, short-term, and evidence-based treatment developed in tandem with the validation of the PGD diagnosis. To facilitate the dissemination of PGDT training, we developed a web-based therapist tutorial that includes didactic training on PGDT concepts and principles as well as web-based multimedia patient scenarios and examples of clinical implementation of PGDT. OBJECTIVE: We aimed to evaluate user satisfaction with the tutorial and whether the tutorial increased trainees' knowledge of PGDT principles and procedures. Moreover, we included a small number of pilot questions to evaluate the PGDT-related clinical skills. METHODS: This study evaluated tutorial learning using a pre- and poststudy design. Participants were recruited from professional organization mailing lists, announcements to graduates of the Columbia School of Social Work, and through word of mouth. After signing consent, participants completed a brief demographic survey, a 55-item multiple-choice prestudy test on the concepts and principles of PGD and PGDT covered in the tutorial, and a 4-item pilot web-based prestudy test to gauge PGD clinical implementation skills. The link to the course content was then activated, and participants were given 8 weeks to complete the 11-module tutorial containing information, web-based exercises, simulated patient and video examples, and self-tests. RESULTS: Overall, 406 clinicians signed consent, and 236 (58.1%) started the tutorial. Of these, 83.1% (196/236) completed all 11 modules. Trainee scores on our PDGT assessment improved substantially from pretraining to the postmodule assessment, with the total number of correct answers increasing from a mean of 29 (SD 5.5; 52.7% correct) to 36.7 (SD 5.2; 66.7% correct; t195=18.93; P<.001). In addition, the trainee's implementation scores on 4 clinical vignettes increased from 2.6 (SD 0.7) correct out of 4 to 3.1 (SD 0.4) out of 4 (t188=7.02; P<.001). Effect sizes (Cohen d) were 1.44 (95% CI 1.23-1.65) for PDGT assessment and 1.06 (95% CI 0.84-1.29) for implementation. Trainees found the tutorial interesting, enjoyable, clearly presented, and useful for professional development. They endorsed a mean score of 3.7 (SD 0.47) on a 1 to 4 scale of agreement with recommending the course to others and feeling satisfied with the tutorial, and a mean of 3.3 (SD 0.57) with feeling able to apply the skills with clients. CONCLUSIONS: This pilot study provides support for the usefulness of this web-based training for teaching clinicians how to administer PGDT. The addition of patient scenarios for clinical implementation strategies holds promise for increasing the effectiveness of PGDT training and other evidence-based treatments. TRIAL REGISTRATION: ClinicalTrials.gov NCT05121792; https://www.clinicaltrials.gov/ct2/show/NCT05121792.

Social Determinants Associated With Exposure to Childhood Parental Bereavement and Subsequent Risk for Psychiatric Disorders.

Importance: Prevalence of childhood parental death varies by race and ethnicity and socioeconomic status, yet whether similar variation persists in the association with lifetime psychiatric disorder is unknown. Objective: To assess whether race and ethnicity and parental educational attainment are associated with the risk of death of a parent; to determine whether the risk for lifetime psychiatric disorder associated with death of a parent was moderated by race and ethnicity and highest parental educational attainment; and to examine a potential intersection of race and ethnicity with parental educational attainment in the risk of lifetime psychiatric disorder associated with death of a parent. Design, Setting, and Participants: This retrospective cohort study used data from the National Comorbidity Study: Adolescent Supplement (NCS-A), 2001 to 2004. Participants included youth aged 13 to 18 years, restricted to Black, Hispanic, and White youth due to power limitations. Data were analyzed from February 26, 2021, to April 21, 2022. Exposure: Death of a parent during childhood. Main Outcomes and Measures: The primary study outcome was any lifetime Diagnostic and Statistical Manual of Mental Disorders (Fourth Edition) psychiatric disorder, assess via assessed via structured clinical interviews. Results: Among 9501 youth (mean [SD] age, 15.2 [1.5] years; 50.9% female), including 511 youth who had experienced parental death and 8990 youth who had not, the cumulative hazard of parental death by age 18 years was approximately doubled for Hispanic (10.1%; 95% CI, 6.9%-14.7%) and Black (14.0%; 95% CI, 10.6%-18.4%) youth compared with White youth (6.0%; 95% CI, 4.7%-7.8%). Similar patterns were noted by parental educational attainment: the cumulative hazard of parental death for youth of parents with less educational attainment was nearly double (10.1%; 95% CI, 8.1%-12.6%) compared with youth of parents with more education (6.6%; 95% CI, 5.2%-8.4%). Death of a parent was positively and significantly associated with risk of any lifetime psychiatric disorder (aOR, 1.34; 95% CI, 1.03-1.75) compared with youth who had not experienced death of a parent. However, this association was not moderated by race and ethnicity (aOR, 1.05; 95% CI, 0.58-1.92) or parental educational attainment (aOR, 1.19; 95%, 0.70-2.04), although power analyses suggest that larger sample sizes are needed. Conclusions and Relevance: In this cross-sectional study, Black and Hispanic youth experienced elevated parental death compared with White youth, yet the risk for any lifetime psychiatric disorder after parental death was not significantly moderated by race and ethnicity or parental education. Both individual- and population-level interventions may be needed to address the increased risk of psychiatric disorders, although additional studies with larger sample sizes are needed.

Change in avoidance and negative grief-related cognitions mediates treatment outcome in older adults with prolonged grief disorder.

Objective: The present study investigated the role of the two theoretically derived mediators in the treatment of Prolonged Grief Disorder (PGD). Mediators were changes in avoidance and maladaptive cognitions. An additional hypothesis tested whether these candidate mediators are specific to CBT-based Complicated Grief Treatment (CGT) compared to Interpersonal Therapy (IPT). Method: We performed secondary analyses with assessment completers (n = 131) from a randomized-controlled trial with older adults with PGD. Patients received 16 sessions of CGT or IPT. Outcomes were treatment response and reductions in grief symptoms and grief-related related impairment. Results: Reductions in avoidance between baseline and week 16 mediated reductions in grief symptoms and grief-related impairment. Reductions in maladaptive grief-related cognitions over the same period mediated treatment response, reductions in grief symptoms and grief-related impairment. There were no significant treatment-mediator interactions. We could not establish that mediators changed before the outcomes. Conclusion: Results are consistent with theoretical models of PGD, including the CGT treatment model. Despite different therapeutic procedures, we found no significant interaction effect, but CGT produced larger effects. Future research needs to establish a timeline of change through the use of multiple measurements of mediators and outcomes.Trial registration: ClinicalTrials.gov identifier: NCT01244295.

Grief-related beliefs in shidu parents with and without prolonged grief disorder: Psychometric properties of a Chinese version of the Typical Beliefs Questionnaire.

The Typical Beliefs Questionnaire (TBQ) assesses common grief-related cognitions, which demonstrated satisfactory psychometric properties in a treatment-seeking sample with prolonged grief disorder (PGD). Chinese shidu parents (bereaved parents over the age of 49 who have lost their only child) are at a high risk of PGD. The current study aimed to examine psychometric properties of the Chinese version of the TBQ (TBQ-C) in a community sample of shidu parents with and without PGD, to compare this to the original validation clinical sample in the United States bereaved of any close relationship and to consider its use as a clinical tool. We examined the rate of positive endorsement, factor structure, internal consistency and validity of the TBQ-C in 310 community-based shidu parents (including 102 who met the criteria for PGD). Results showed that the rate of positive endorsement for each item ranged from 7.2% to 48.6% among non-PGD participants and from 20.6% to 92.2% among PGD participants. Confirmatory factor analysis indicated that the original five-factor structure fit both the non-PGD and PGD shidu parents. The TBQ-C showed acceptable internal consistency and satisfactory convergent and concurrent validity in both groups. It had good discriminant validity and can be helpful in distinguishing shidu parents with and without PGD. The TBQ-C can be used to investigate common grief-related beliefs that may be problematic for both shidu parents with and without PGD.

Grief and the COVID-19 Pandemic in Older Adults.

(Appeared originally in Am J Geriatr Psychiatry 2020; 28:10 1119-1125).

Posttraumatic Distress Symptoms and Their Response to Treatment in Adults With Prolonged Grief Disorder.

OBJECTIVE: Posttraumatic stress disorder and prolonged grief disorder (PGD) arise following major life stressors and may share some overlapping symptomatology. This study aimed to examine the presence and response to treatment of posttraumatic stress symptoms (PTSS) in bereaved adults with a primary diagnosis of PGD. METHODS: A randomized controlled trial of 395 adults with PGD (defined as an Inventory of Complicated Grief score ≥ 30 plus confirmation on structured clinical interview) randomly assigned participants to either complicated grief treatment (CGT) with citalopram, CGT plus placebo, citalopram, or placebo between March 2010 and September 2014. This secondary analysis examined the presence of PTSS (per the Davidson Trauma Scale) at baseline and change in PTSS with treatment using longitudinal mixed-effects regression and examined the role of violent compared to nonviolent deaths (loss type). RESULTS: High levels of PTSS were present at baseline, regardless of loss type, and were associated with increased functional impairment (P < .001). CGT with placebo demonstrated efficacy for PTSS compared to placebo in both threshold (OR = 2.71; 95% CI, 1.13-6.52; P = .026) and continuous (P < .001; effect size d = 0.47) analyses, and analyses were suggestive of a greater effect for CGT plus citalopram compared to citalopram alone (threshold analysis: OR = 2.84; 95% CI, 1.20-6.70; P = .017; continuous analysis: P = .053; d = 0.25). In contrast, citalopram did not differ from placebo, and CGT plus citalopram did not differ from CGT plus placebo. CONCLUSIONS: Bereavement-related PTSS are common in bereaved adults with PGD in the context of both violent and nonviolent death and are associated with poorer functioning. CGT shows efficacy for PTSS, while the antidepressant citalopram does not. TRIAL REGISTRATION: : ClinicalTrials.gov identifier: NCT01179568.

Grief and the COVID-19 Pandemic in Older Adults.

In few periods in human history have bereavement and grief been on so many people's minds as they are today. As the coronavirus disease 2019 (COVID-19) ravages the world, we have seen many perish in a short time. Many have died alone because of requirements for physical distancing. Even more will succumb as COVID-19 continues to spread. Moreover, deaths from other causes, numbering over 50 million annually, are also happening amid physical distancing and other COVID-19-related challenges. The pandemic is affecting the way terminally ill patients are being cared for, when and how people are dying of other causes, and how bodies are being handled and bereavement rituals performed. The bereaved are required to grieve without the support of usual social and cultural rituals. Grieving is further encumbered by cascading life stressors deriving from policies needed to mitigate the pandemic. Though we are often heartened by human resilience in response to death and other hardships, for some, the burden of this pandemic will be too much. Among other mental health problems, we will likely see an increase in prolonged grief disorder. In this commentary, we review the new diagnosis of prolonged grief disorder and outline why we might anticipate increased rates of this condition on the heels of COVID-19, especially among older persons. The authors suggest ways that might mitigate this emerging problem.

Grief Before and After Bereavement in the Elderly: An Approach to Care.

Grief is the natural response to the death of a loved one and is encountered frequently in clinical practice with the elderly; it can also precede the death. Knowledge about four distinct forms of grief can aid clinicians with the conceptualization of grief, and the assessment and care of grievers. First, predeath grief is experienced by many caregivers of terminally ill patients. Second, acute grief arises immediately after the death of a loved one; and third, this normally evolves to a permanent state of integrated grief after a process of adaptation. Finally, failure of adaptation results in Prolonged Grief Disorder (PGD) which has been recently included in ICD-11. The hallmark feature of PGD is intense longing for the deceased or persistent preoccupation with the deceased that lasts longer than 6 months after the death. Validated instruments are available to assist practitioners with assessment of predeath grief and screening for PGD, thereby enabling identification of patients in need of additional support. Increased risks of morbidity and mortality following bereavement are important health issues for clinicians to be aware of. All grievers can benefit from support focused on understanding their grief, managing emotional pain, thinking about the future, strengthening their relationships, telling the story of the death, learning to live with reminders of the deceased, and connecting with memories. A short-term evidence-based intervention for PGD is based upon these seven themes and is efficacious in the elderly. Caregivers of the terminally ill benefit from psychological support that validates and normalizes their grief experiences and helps them recognize and accept their losses.

Impact of sleep on complicated grief severity and outcomes.

BACKGROUND: Complicated grief (CG) is characterized by persistent, impairing grief after losing a loved one. Little is known about sleep disturbance in CG. Baseline prevalence of subjective sleep disturbance, impact of treatment on sleep, and impact of mid-treatment sleep on CG and quality of life outcomes were examined in adults with CG in secondary analyses of a clinical trial. METHODS: Patients with CG (n = 395, mean age =53.0; 78% female) were randomized to CGT+placebo, CGT+citalopram (CIT), CIT, or placebo. Subjective sleep disturbance was assessed by a grief-anchored sleep item (Pittsburgh Sleep Quality Index: PSQI-1) and a four-item sleep subscale of the Quick Inventory of Depressive Symptomatology (QIDS-4). Sleep disturbance was quantified as at least one QIDS-4 item with severity ≥2 or grief-related sleep disturbance ≥3 days a week for PSQI-1. Outcomes included the Inventory of Complicated Grief (ICG), Work and Social Adjustment Scale (WSAS), and Clinical Global Impressions Scale. RESULTS: Baseline sleep disturbance prevalence was 91% on the QIDS-4 and 46% for the grief-anchored PSQI-1. Baseline CG severity was significantly associated with sleep disturbance (QIDS-4: p = .015; PSQI-1: p = .001) after controlling for comorbid depression and PTSD. Sleep improved with treatment; those receiving CGT+CIT versus CIT evidenced better endpoint sleep (p = .027). Mid-treatment QIDS-4 significantly predicted improvement on outcome measures (all p < .01), though only WSAS remained significant after adjustment for mid-treatment ICG (p = .02). CONCLUSIONS: Greater CG severity is associated with poorer sleep beyond PTSD and depression comorbidity. Additional research including objective sleep measurement is needed to optimally elucidate and address sleep impairment associated with CG.

Commentary on evidence in support of a grief-related condition as a DSM diagnosis.

The death of a loved one is one of life's greatest stressors. Most bereaved individuals experience a period of acute grief that diminishes in intensity as they adapt to the changes brought about by their loss. Over the past four decades, a growing body of research has focused on a form of prolonged grief that is painful and impairing. There is a substantial and growing evidence base that supports the validity and significance of a grief-related disorder, including the clinical value of being able to diagnose it and provide effective targeted treatment. ICD-11 will include a new diagnosis of prolonged grief disorder (PGD). DSM-5 called this condition persistent complex bereavement disorder (PCBD) and included it in Section III, signaling agreement that a diagnosis is warranted while further research is needed to determine the optimal criteria. Given the remaining uncertainties, reading this literature can be confusing. There is inconsistency in naming the condition (including complicated grief as well as PGD and PCBD) and lack of uniformity in identifying it, with respect to the optimal threshold and timeframe for distinguishing it from normal grief. As an introductory commentary for this Depression and Anxiety special edition on this form of grief, the authors discuss the history, commonalities, and key areas of variability in identifying this condition. We review the state of diagnostic criteria for DSM-5 and the current ICD-11 diagnostic guideline, highlighting the clinical relevance of making this diagnosis.

Optimizing the clinical utility of four proposed criteria for a persistent and impairing grief disorder by emphasizing core, rather than associated symptoms.

BACKGROUND: Distinguishing a disorder of persistent and impairing grief from normative grief allows clinicians to identify this often undetected and disabling condition. As four diagnostic criteria sets for a grief disorder have been proposed, their similarities and differences need to be elucidated. METHODS: Participants were family members bereaved by US military service death (N = 1732). We conducted analyses to assess the accuracy of each criteria set in identifying threshold cases (participants who endorsed baseline Inventory of Complicated Grief ⩾30 and Work and Social Adjustment Scale ⩾20) and excluding those below this threshold. We also calculated agreement among criteria sets by varying numbers of required associated symptoms. RESULTS: All four criteria sets accurately excluded participants below our identified clinical threshold (i.e. correctly excluding 86-96% of those subthreshold), but they varied in identification of threshold cases (i.e. correctly identifying 47-82%). When the number of associated symptoms was held constant, criteria sets performed similarly. Accurate case identification was optimized when one or two associated symptoms were required. When employing optimized symptom numbers, pairwise agreements among criteria became correspondingly 'very good' (κ = 0.86-0.96). CONCLUSIONS: The four proposed criteria sets describe a similar condition of persistent and impairing grief, but differ primarily in criteria restrictiveness. Diagnostic guidance for prolonged grief disorder in International Classification of Diseases, 11th Edition (ICD-11) functions well, whereas the criteria put forth in Section III of Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5) are unnecessarily restrictive.

Changes in typical beliefs in response to complicated grief treatment.

BACKGROUND: Prolonged grief disorder (PGD) is a new diagnosis in the 11th edition of the International Classification of Diseases, estimated to affect 1 in 10 bereaved people and causing significant distress and impairment. Maladaptive thoughts play an important role in PGD. We have previously validated the typical beliefs questionnaire (TBQ), which contains five kinds of thinking commonly seen in PGD: protesting the death, negative thoughts about the world, needing the person, less grief is wrong, and grieving too much. The current paper examines the role of maladaptive cognition as measured by the TBQ in PGD and its change with treatment. METHODS: Among participants in a multisite clinical trial including 394 adults, we examined (a) the relationship between maladaptive thoughts at baseline and treatment outcomes, (b) the relationship between maladaptive thoughts and suicidality at baseline and posttreatment, and (c) the effect of treatment with and without complicated grief therapy (CGT) on maladaptive thinking. RESULTS: TBQ scores were associated with treatment outcomes and were strongly related to suicidal thinking before and after treatment. TBQ scores showed significantly greater reduction in participants who received CGT with citalopram versus citalopram alone (adjusted mean standard error [SE] difference, -2.45 [0.85]; p = .004) and those who received CGT with placebo versus placebo alone (adjusted mean [SE] difference, -3.44 [0.90]; p < .001). CONCLUSIONS: Maladaptive thoughts, as measured by the TBQ, have clinical and research significance for PGD and its treatment.

Complicated grief therapy for clinicians: An evidence-based protocol for mental health practice.

In the United States alone, about 10 million persons are newly bereaved each year. Most do not require professional intervention or treatment, but many can benefit from targeted support. However, a significant minority of bereaved persons experience intense, prolonged and disabling grief symptoms associated with considerable morbidity and mortality (aka, "Complicated Grief"). Individuals with Complicated Grief require more formal interventions. In this article, we describe a compassionate and evidence-based approach to bereavement-care that can be provided in varied mental health settings. For individuals struggling with acute grief, clinicians can help by providing recognition and acceptance of the grief, eliciting and compassionately listening to their narratives of their relationship with the deceased and the death, and regularly "checking in" regarding their grief experiences. For bereaved persons who are experiencing Complicated Grief, we recommend an evidence-based approach to bereavement-care, complicated grief therapy (CGT), that involves helping the individual accept and cope with the loss while simultaneously assisting them with adaptation to life without the deceased. We describe ways of implementing CGT's seven core themes: (1) understanding and accepting grief, (2) managing painful emotions, (3) planning for a meaningful future, (4) strengthening ongoing relationships, (5) telling the story of the death, (6) learning to live with reminders, and (7) establishing an enduring connection with memories of the person who died. This work can be done in a variety of settings, taking into consideration the needs of the patient, the limitations of the setting, and the skills and experiences of each clinician.

Mental health conditions in bereaved military service widows: A prospective, case-controlled, and longitudinal study.

BACKGROUND/OBJECTIVES: Bereavement is associated with increases in prevalence of mental health conditions and in healthcare utilization. Due to younger age and bereavement by sudden and violent deaths, military widows may be vulnerable to poor outcomes. No systematic research has examined these effects. METHOD: Using outpatient medical records from wives of active-duty military service members (SMs), we compared the prevalence of mental health conditions and mental healthcare visits among case widows (n = 1,375) to matched (on age, baseline healthcare utilization, SM deployment, and rank) nonbereaved control military wives (n = 1,375), from 1 year prior (Yr-1) to 2 years following (Yr+1 and Yr+2) SM death. Prevalence risk ratios and confidence intervals were compared to determine prevalence rates of mental health conditions and outpatient mental healthcare visits over time. RESULTS: The prevalence of any mental health condition, as well as a distinct loss- and stress-related mental health conditions, significantly increased from Yr-1 to Yr+1 and Yr+2 for cases as did mental healthcare utilization. Widows with persistent disorders (from Yr+1 to Yr+2) exhibited more mental conditions and mental healthcare utilization than widows whose conditions remitted. CONCLUSION: Bereavement among military widows was associated with a two- to fivefold increase in the prevalence of depression, posttraumatic stress disorder, and adjustment disorder postdeath, as well as an increase in mental healthcare utilization. An increase in the prevalence of loss- and stress-related conditions beyond 1 year after death indicates persistent loss-related morbidity. Findings indicate the need for access to healthcare services that can properly identify and treat these loss-related conditions.

Integrating multiple-domain rules for disease classification.

In psychiatry, clinicians use criteria sets from the Diagnostic and Statistical Manual of Mental Disorders to diagnose mental disorders. Most criteria sets have several symptom domains, and in order to be diagnosed, an individual must meet the minimum number of symptoms required by each domain. Some efforts are now focused on adding biomarkers to these symptom domains to facilitate the detection of and highlight the neurobiological basis of psychiatric disorders. Thus, a new criteria set may consist of both clinical symptom counts in several domains and continuous biomarkers. In this paper, we propose a method to integrate classification rules from multiple data sources to estimate an optimal criteria set. Each domain-specific rule can be counts of symptoms, a linear function of symptoms, or even nonparametric. The overall classification rule is the intersection of these domain-specific rules. Based on examining the expected population loss function, we propose two iterative algorithms using either support vector machines or logistic regression to fit intersection rules consistent with the Diagnostic and Statistical Manual of Mental Disorders. In simulation studies, these proposed methods are comparable with the true decision rule. The methods are applied to the motivating study to construct a criteria set for complicated grief. The developed criteria set shows a substantial improvement in sensitivity and specificity compared to the current standards on an independent validation study.