Improvement of quality of life in patients with benign goiter after surgical treatment

The Impact of Post-Thyroidectomy Neck Stretching Exercises on Neck Discomfort, Pressure Symptoms, Voice and Quality of Life: A Randomized Controlled Trial

Background

Methods

Results

Conclusions

Quality of Life in Patients with Benign Non-Toxic Goiter After Surgical Intervention: A Systematic Review and Meta-Analysis

BACKGROUND

Prior studies evaluating health-related quality of life (HR-QoL) outcomes in patients undergoing surgery for benign non-toxic goiter have used different instruments and time points, leading to conflicting results. We sought to systematically review the differences in HR-QoL among patients with BNTG at baseline and 6 months after surgery, using exclusively the ThyPRO questionnaire.

METHODS

A systematic search was performed using PubMed, Embase, Web of Science, Cochrane Central, CINAHL, and PsycINFO for papers reporting the assessment of HR-QoL utilizing ThyPRO. Data were meta-analyzed using a random-effects model, and pooled estimates were calculated using weighted mean differences (WMD) between baseline and 6 months after surgery. We assessed the quality and risk of bias of the studies using the Robins-I tool and previously published minimally important change (MIC) values to assess clinical significance.

RESULTS

Six papers met the predefined inclusion criteria, describing a total of 496 patients. Meta-analysis demonstrated improved QoL in all thirteen domains of ThyPRO six months post-surgical intervention compared to baseline. Specifically, the largest improvement in QoL was seen in the domains of overall QoL, WMD -25.84 (95% CI -29.70, -21.98, p < 0.001, I² = 23%), goiter symptoms, 23.96 (95% CI -30.29, -17.64, p < 0.001, I² = 91%), and tiredness, -16.20 (95% CI -19.23, -13.16, p < 0.001, I² = 3%). The differences in scores 9 of 13 domains were clinically significant based on MIC.

CONCLUSIONS

Disease-specific HR-QoL improved in all ThyPRO domains after surgery in patients with BNTG. Future studies of QoL in thyroid surgery patients will benefit from a standard questionnaire and improved reporting of covariates including complications to ensure comparability across studies.

Comparison of effects of energy based devices on quality of life after sutureless thyroidectomy

OBJECTIVE

In current literature, no studies evaluated effect of energy-based vessel-sealing-devices on quality of life after sutureless total thyroidectomies. This study aimed to identify any potential differences between two energy-based vessel-sealing-devices (Harmonic Focus, Ligasure LF1212) in patients with benign thyroid disorders who underwent sutureless total thyroidectomy.

MATERIALS AND METHODS

Differences in quality of life of patients were evaluated using data obtained by Thy-PRO-39-Tr questionnaire prior to and four-week after surgery. Total and domain-based alterations in quality of life were compared between groups according to energy-based vessel-sealing-devices type (Group L, Group H). Additionally, data including demographics, height, weight, body mass index, neck circumference, sternomental distance were collected.

RESULTS

Of 1032 patients, 200 were eligible for study, at the end 193 were analysed. There were no differences between groups in terms of age, sex, body mass index, tobacco use. Analysis did not reveal any differences in overall quality of life between groups (P = .42). However, in "eye symptoms" (P < .001) and "cognitive functions" (P = .002) domains, Harmonic provided statistically improved quality of life. Effect on cognitive function was greater in patients of advanced age.

CONCLUSIONS

Especially in elderly patients with worsening eye conditions and cognitive functions, use of Harmonic may enhance patients' outcome by increasing quality of life in addition to optimizing surgical outcome when compared to Ligasure.

Impact of thyroidectomy on quality of life in benign goitres: results from a prospective cohort study

PURPOSE

Benign thyroid diseases encompass a large spectrum of conditions that are chronic and subtle in nature. A majority of patients choose non-surgical management and continue living their daily lives with subconscious impairment of optimal functioning. We studied the effect of thyroidectomy on the quality of life (QoL) in patients with benign goitres.

METHODS

A prospective study was conducted on 50 patients between January 2017 and August 2018 using the ThyPRO 39 questionnaire. This is a disease-specific health-related questionnaire administered the day before surgery and 6 months following surgery. Data analysis was performed using EpiData Manager and EpiData Entry Client (v 3.1).

RESULTS

The mean age of the cohort was 43.30 years ± 11.61, with a female preponderance (34:16). The most common indications for surgery were suspicion of malignancy and compressive symptoms in 34% and 30%, respectively. The most common histopathology reported was nodular/adenomatous hyperplasia (56%). Prior to surgery, the most common domains affected were emotional susceptibility and tiredness. Following surgery, a significant improvement in all domains of the ThyPRO 39 questionnaire were seen except for psychological well-being (p=0.126). In addition, the composite scores significantly improved (p<0.001). Younger age, female gender, and longer duration of goitre were the factors that significantly affected the outcomes in various domains.

CONCLUSION

Patients with benign goitres have subtle impairment of QoL which showed significant improvement following thyroidectomy.

Eye symptoms in patients with benign thyroid diseases

Thyroid diseases may cause a variety of functional and structural body changes, including eye and vision abnormalities, which can have a negative impact on a patient’s well-being. However, only a few studies on the impact of other benign thyroid diseases on the visual process are available in the literature. In this study, using the Polish version of the thyroid-specific quality of life (ThyPROpl) questionnaire, we aimed to determine the self-reported influence of benign thyroid diseases (e.g., nodular goiter, toxic nodular goiter, Graves’ disease, thyroid orbitopathy, Hashimoto’s thyroiditis, and surgical hypothyroidism) on patients’ eyes and vision. This was a prospective study. In total, 374 randomly selected euthyroid patients and 255 control subjects responded to the ThyPROpl questionnaire and the results were evaluated. Nearly 69% of the respondents reported that the most frequent condition was “reduced sight.” Men most often reported wet/tearing eyes (66%). The occurrence of eyelid sacks or swollen eyelids (64%), ophthalmalgia (62%), and eye dryness (61%) was marked almost as often. In total, 29% of the patients reported diplopia, and it was found to be most prevalent among those with thyroid orbitopathy. Other complaints were similarly prevalent among all the subgroups. A positive correlation was also observed between the scores of the “eye symptoms” and other ailments. Except for swelling around the lower eyelids, patients with thyroid diseases more frequently experienced all of the ocular complaints analyzed in this study compared with controls. This study showed that eye complaints are common in patients with benign thyroid diseases and ocular disturbances have a negative impact on the overall quality of life of patients.

How does thyroidectomy for benign thyroid disease impact upon quality of life? A prospective study

BACKGROUND

Choosing which patients to recommend surgery for benign thyroid conditions can be difficult due to the subjective nature of compressive thyroid and hormonal symptoms. The aim of this prospective study was to analyse changes in quality of life (QOL) following thyroid surgery using a validated disease-specific assessment tool, the thyroid-related patient-reported outcome (ThyPRO) questionnaire.

METHODS

Participants undergoing elective thyroid surgery for benign conditions were recruited. Patient demographics and clinical data were collected. ThyPRO consists of 85 questions grouped into 13 physical, mental and social symptom domains. Patients completed a ThyPRO questionnaire pre-operatively and at 6 weeks and 6 months post-operatively. ThyPRO items were scored according to protocol to produce 13 subscales. Repeated measures linear models with no random effects were performed using data for each outcome.

RESULTS

Results were available for a total of 72 patients. The sample was predominately female (n = 63, 88%) with average age 49.8 years. The majority of patients underwent surgery for multi-nodular goitre. At 6 weeks post-operatively, significant improvement was demonstrated in the goitre, hypothyroid, hyperthyroid and anxiety symptom domains. At 6 months post-operatively, significant improvement was demonstrated in all but four domains. No domains demonstrated significant increase in impairment post-operatively.

CONCLUSION

Patients had significant improvement in nine of 13 symptom domains following surgery. Patients did not experience a negative impact on QOL following surgery. Further studies with larger patient cohorts may be able to identify potential pre-operative predictive factors for a post-operative improvement in QOL for benign thyroid disease.

Quality of life is not affected by thyroid surgery in nontoxic benign goitre in long-term surveillance-A prospective observational study

OBJECTIVE

Quality of life (QoL) has so far seldom been taken into account by default in decision-making for surgical indication in thyroid surgery. Therefore, we compared pre- and postoperative QoL of patients using the EuroQoL-5D (EQ-5D) questionnaire. The influence of certain socio-economic factors on QoL as a second end-point was considered.

DESIGN

Prospective cohort study.

PATIENTS

About 153 patients with euthyroid symptomatic benign goitre after hemi- and total thyroidectomy (follow-up 83.6%) have been included.

MEASUREMENTS

The EQ-5D questionnaire was used prior to and 1 year after surgery. In addition, a questionnaire for assessment of socio-economic status was collected.

RESULTS

For n = 90 (n = 67 female, n = 23 male), total thyroidectomy (TT) and, for n = 63 (n = 45 female, n = 18 male), hemithyroidectomy (HT) were performed. None permanent dysfunction of the vocal cord was recorded. Transient symptomatic hypocalcaemia was detected in 9% of the thyroidectomy group (8/90 patients). At follow-up, 86% of patients showed either no change or improved QoL. About 14% of patients complained of deteriorated QoL, regardless of the extent of surgery. Socio-economic factors did not influence postoperative QoL.

CONCLUSIONS

Results indicate that in pre-operative consultation of patients with benign goitre, the improvement of QoL should be taken into account for decision-making in cases of ambiguous surgical indication. Contrary to current discussions that too much thyroid surgery is performed in Germany, we can recommend presenting surgery as an equivalent option to watchful waiting as QoL is at least preserved or improved. The extension of the resection should, however, be decided individually.

The Impact of Post-thyroidectomy Paresis on Quality of Life in Patients with Nodular Thyroid Disease

Objective

To investigate the impact of postoperative paresis on disease-specific quality of life (DSQoL) after thyroidectomy in patients with benign nodular thyroid disease.

Study Design

Observational study.

Setting

University hospital.

Subjects and Methods

Patients were evaluated before and 3 weeks and 6 months after surgery in an individual prospective cohort study using videolaryngostroboscopy (VLS), voice range profile, voice handicap index (VHI), multidimensional voice program, maximum phonation time (MPT), and auditory perceptual evaluation. Changes in DSQoL were assessed by the Thyroid-specific Patient-Reported Outcome measure. Cohen’s effect size was used to evaluate changes.

Results

Sixty-two patients were included, 55 of whom completed all examinations. Three weeks after surgery, a blinded VLS examination showed signs of paresis of either the recurrent laryngeal nerve or the external branch of the superior laryngeal nerve (RLN/EBSLN) in 13 patients (24%). A paresis corresponded to a 12 ± 28 point increase in VHI ( P = .002) and was associated with a significant 4.3 ± 7.5 semitone decrease in the maximum fundamental frequency ( P < .001) and a 5.3 ± 8.2 dB reduction in maximum intensity. Further, it was associated with a 4.5 ± 11.2 second reduction in MPT ( P = .001) and an increase of 0.40 ± 1.19 in grade, 0.42 ± 1.41 in roughness, and 0.36 ± 1.11 in breathiness. Signs of postoperative RLN/EBSLN paresis correlated with an 11.0-point ( P = .02) poorer improvement in goiter symptoms at both 3 weeks and 6 months after surgery.

Conclusion

Signs of RLN/EBSLN paresis after thyroidectomy were associated with less pronounced improvement in goiter symptoms in patients with thyroid nodular disease. However, thyroidectomy was associated with an overall improved DSQoL by 6 months after surgery.

The Impact of Esophageal Compression on Goiter Symptoms before and after Thyroid Surgery

INTRODUCTION

Benign nodular goiter may be associated with swallowing difficulties, but insight into the associated pathophysiology is limited. The aim of this study was to investigate the effect of surgery on the degree of esophageal compression, and its correlation to swallowing difficulties.

METHODS

Esophageal compression and deviation were evaluated blindly on magnetic resonance imaging (MRI) of the neck, prior to and 6 months after thyroid surgery for symptomatic benign goiter. Goiter symptoms and swallowing difficulties were measured by the Goiter Symptom Scale of the Thyroid-Specific Patient-Reported Outcome (ThyPRO) questionnaire. Cohen's d was used for evaluating effect sizes (ES).

RESULTS

Sixty-four patients completed the study. Before surgery, median goiter volume was 57 (range 14-642) mL. The smallest cross-sectional area of the esophagus (SCAE) increased from a median of 95 (47-147) to 137 (72-286) mm² (ES = 1.31, p < 0.001). Median esophagus width increased from 15 (range 10-21) to 17 (range 12-24) mm (ES = 0.94, p < 0.001) after surgery, while no statistically significant change was observed for the sagittal dimension (anterior-to-posterior), thus reflecting an increasingly ellipsoid esophageal shape. Median esophageal deviation decreased moderately after surgery from 4 (0-23) to 3 (0-10) mm (ES = 0.54, p = 0.005). The goiter symptom score improved considerably from (mean ± SD) 40 ± 21 to 10 ± 10 points (ES = 1.5, p < 0.001) after surgery, and the improvements were associated with improvements in SCAE (p = 0.03).

CONCLUSIONS

In patients with goiter, thyroidectomy leads to substantial improvements in esophageal anatomy, as assessed by MRI, and this correlates with improved swallowing symptoms. This information is valuable in qualifying the dialogue with goiter patients, before deciding on the mode of therapy. Clinicaltrials.gov (NCT03072654).

The Impact of Goiter and Thyroid Surgery on Goiter Related Esophageal Dysfunction. A Systematic Review

Background: Patients with goiter referred for thyroidectomy report swallowing difficulties. This might be associated with esophageal compression and deviation as this is present in a significant number of patients. Studies on how goiter and subsequently its treatment affect the esophagus are sparse and point in various directions. Our aim was to investigate, through a systematic review, the impact of goiter and thyroidectomy on esophageal anatomy, esophageal physiology, and subjective swallowing dysfunction. Methods: The search period covered 1 January 1975 to 1 July 2018, using the scientific databases PubMed and EMBASE. Inclusion criteria were adult patients with goiter who were either observed or underwent thyroidectomy. Search terms were variations of the terms for goiter, esophagus, swallowing, and dysphagia. From an initial 3,040 titles, 55 full text evaluations led to the final inclusion of 27 papers. Seventeen papers investigated, prospectively, the impact of thyroidectomy on the esophagus, while five observational and five retrospective studies were also included. Results: Esophageal anatomy impairment: Esophageal deviation occurred in 14% and esophageal compression in 8-27% of goiter patients. The prevalence increased with goiter size and with the extent of substernal extension. The smallest cross-sectional area of the esophagus increased by median 34% after thyroidectomy. Esophageal physiology changes: Goiter patients had increased esophageal transit time, positively correlated with goiter size, but unrelated to esophageal motility disturbances. Decrease in the upper esophageal sphincter pressure occurred early after surgery, and normalized within 6 months. Swallowing related patient-reported outcomes: Evaluated by validated questionnaires, swallowing symptoms worsened in the early period after thyroidectomy, but improved after 6 months, as compared to baseline. Conclusions: Thyroidectomy relieved patients with goiter from dysphagia, within 6 months of surgery probably via increase in the cross-sectional area of the esophagus. Attention to the impact by goiter on the esophagus is needed, and balanced and individualized information about the potential benefits and risks of thyroid surgery is crucial in the management of patients with goiter.

Changes in Swallowing Symptoms and Esophageal Motility After Thyroid Surgery: A Prospective Cohort Study

INTRODUCTION

Swallowing difficulties, the pathophysiology behind which is incompletely understood, have been reported in 47-83% of goiter patients referred for thyroidectomy. We aimed at examining the influence of thyroid surgery on swallowing symptoms and esophageal motility.

METHODS

Thirty-three patients with benign nodular goiter undergoing thyroid surgery were included. All completed high-resolution esophageal manometry examinations and the goiter symptom scale score, assessed by the thyroid-specific patient-reported outcome measure. The evaluations were performed before and 6 months after surgery.

RESULTS

Before surgery, the goiter symptom score was median 39 points (range 2-61), which improved to median five points (range 1-52) after surgery (p < 0.001). The motility parameters were within the limits of normal swallowing physiology, both before and after surgery. Only the upper esophageal sphincter (UES) pressure increased significantly from 70.6 ± 27.7 to 87.7 ± 43.2 mmHg after surgery (p = 0.04). Using regression analyses, there was no significant correlation between change in goiter symptoms and weight of the removed goiter, motility parameters, or motility disturbances. However, patients undergoing total thyroidectomy experienced a larger reduction in pressure in the area of the UES and former thyroid gland after surgery in comparison with patients undergoing less extensive surgery.

CONCLUSIONS

Goiter symptoms improved significantly after thyroidectomy, but without correlation to esophageal motility disturbances. This information is essential when interpreting dysphagia in patients with nodular goiter, and when balancing patients' expectations to surgical goiter therapy.

REGISTRATION NUMBER

NCT03100357 ( www.clinicaltrials.org ).

The compensatory enlargement of the remaining thyroid lobe following hemithyroidectomy is small and without impact on symptom relief

According to previous studies, hemithyroidectomy results in growth of the remaining thyroid lobe by up to 30% in first 12 months after surgery. However, this estimate is based on imprecise methods, high inter- and intra-observer variability, and lack of blinding of the measurements. Furthermore, it is unknown whether enlargement of the remaining hemi-thyroid interferes with the improvement in symptoms after surgery for goiter. We aimed to assess the impact of postoperative thyroid growth on goiter symptom relief following hemithyroidectomy in patients with benign nodular goiter. Outcomes were measured before and 6 months after hemithyroidectomy in 44 patients. Thyroid volumes were determined by two independent and blinded observers using magnetic resonance imaging (MRI). Inter- and intra-observer variability was visualized by Bland-Altman plots. Goiter symptoms were assessed by the Thyroid-Specific Patient-Reported-Outcome Questionnaire (ThyPRO) on a scale from 0 to 100 points. After hemithyroidectomy, the remaining thyroid lobe was 13.7 ± 6.4 mL, and enlarged by a mean of 1.8 mL over 6 months [95% confidence interval (CI) (1.6; 2.1), p < 0.001], corresponding to an increase of 17% [95% CI (12; 22)]. The Goiter Symptom score improved by 27 points [95% CI (21; 34), p < 0.0001] from median 39 points (range 2-86) at baseline, and was unaffected by the compensatory thyroid growth. Six months after hemithyroidectomy, using blinded MRI evaluations, we demonstrated a small but significant postoperative growth of the remaining hemi-thyroid, which did not significantly affect the considerable improvement in goiter symptoms.

Quality of life after thyroidectomy in patients with nontoxic nodular goiter: A prospective cohort study

BACKGROUND

Using the thoroughly validated Thyroid-Related Quality-of-Life Patient-Reported Outcome (ThyPRO) questionnaire, the purpose of this study was to investigate changes in disease-specific quality of life (QOL) after surgical treatment in patients with benign nontoxic multinodular goiters.

METHOD

Patients with goiters scheduled for thyroid surgery (n = 106) and individuals from the general population (n = 739) were studied. The ThyPRO data before, 3 months, and 6 months after surgery were compared with normative scores from the general population using a linear mixed model and t tests.

RESULTS

Before surgery, patients with goiters experienced poorer scores on all scales compared to the general population. After surgery, moderate to large improvements were seen in goiter symptoms, tiredness, anxiety, and overall QOL. After surgery, all scales returned to values equal to the general population. The degree of anxiety was, in fact, lower than in the general population.

CONCLUSION

Thyroid surgery leads to significant benefit among patients with benign nontoxic goiters by restoring QOL equal to that in the general population.

The prevalence of post-thyroidectomy chronic asthenia: a prospective cohort study

PURPOSE

Chronic asthenia (CA) is complained by some patients that have undergone thyroid surgery. We evaluate its impact in patients undergoing unilateral or bilateral thyroidectomy, the trend during a 1-year follow-up, and the possible risk factors.

METHODS

A prospective, cohort study was carried out on 263 patients scheduled for thyroidectomy from 2012 and 2014. Exclusion criteria were as follows: Graves' disease, malignancies requiring radioiodine therapy, post-surgical hypoparathyroidism, laryngeal nerve palsy, abnormal pre- and post-operative thyroid hormone levels, and BMI outside the normal range. Demographics; smoking and alcoholism addiction; cardiac, pulmonary, renal, and hepatic failure; diabetes; anxiety; and depression were recorded. The Brief Fatigue Inventory (BFI) was used to evaluate CA and its possible association with these comorbidities 6 and 12 months after thyroidectomy.

RESULTS

One hundred seventy-seven patients underwent total thyroidectomy (TT), 54 hemithyroidectomy (HT). Thirty-two patients were not recorded because of the onset of exclusion criteria. In the 6 months after thyroidectomy, in the TT group, 64 patients (36.16%) reported an impairment in the BFI score and only 1 in the TL group. The mean BFI score changed from 1.663(±1.191) to 2.16 (±11.148) in the TT group, from 1.584 (±1.371) to 1.171 (±1.093) in the TL group (p < 0.001). No further significant variations in BFI were reported 1 year after surgery.

CONCLUSIONS

CA worsened after TT, but not after HT. Apart from operative procedure itself, no other risk factor was found be significantly associated with post-thyroidectomy asthenia. Further investigation is needed to determine the causes of CA.

Study protocol; Thyroid hormone Replacement for Untreated older adults with Subclinical hypothyroidism - a randomised placebo controlled Trial (TRUST)

BACKGROUND

Subclinical hypothyroidism (SCH) is a common condition in elderly people, defined as elevated serum thyroid-stimulating hormone (TSH) with normal circulating free thyroxine (fT4). Evidence is lacking about the effect of thyroid hormone treatment. We describe the protocol of a large randomised controlled trial (RCT) of Levothyroxine treatment for SCH.

METHODS

Participants are community-dwelling subjects aged ≥65 years with SCH, diagnosed by elevated TSH levels (≥4.6 and ≤19.9 mU/L) on a minimum of two measures ≥ three months apart, with fT4 levels within laboratory reference range. The study is a randomised double-blind placebo-controlled parallel group trial, starting with levothyroxine 50 micrograms daily (25 micrograms in subjects <50Kg body weight or known coronary heart disease) with titration of dose in the active treatment group according to TSH level, and a mock titration in the placebo group. The primary outcomes are changes in two domains (hypothyroid symptoms and fatigue / vitality) on the thyroid-related quality of life questionnaire (ThyPRO) at one year. The study has 80% power (at p = 0.025, 2-tailed) to detect a change with levothyroxine treatment of 3.0% on the hypothyroid scale and 4.1% on the fatigue / vitality scale with a total target sample size of 750 patients. Secondary outcomes include general health-related quality of life (EuroQol), fatal and non-fatal cardiovascular events, handgrip strength, executive cognitive function (Letter Digit Coding Test), basic and instrumental activities of daily living, haemoglobin, blood pressure, weight, body mass index and waist circumference. Patients are monitored for specific adverse events of interest including incident atrial fibrillation, heart failure and bone fracture.

DISCUSSION

This large multicentre RCT of levothyroxine treatment of subclinical hypothyroidism is powered to detect clinically relevant change in symptoms / quality of life and is likely to be highly influential in guiding treatment of this common condition.

TRIAL REGISTRATION

Clinicaltrials.gov NCT01660126 ; registered 8th June 2012.

Development of a Short Version of the Thyroid-Related Patient-Reported Outcome ThyPRO

BACKGROUND

Thyroid diseases affect quality of life (QoL). The Thyroid-Related Patient-Reported Outcome (ThyPRO) is an international comprehensive well-validated patient-reported outcome, measuring thyroid-related QoL. The current version is rather long--85 items. The purpose of the present study was to develop an abbreviated version of the ThyPRO, with conserved good measurement properties.

METHODS

A cross-sectional (N = 907) and a longitudinal sample (N = 435) of thyroid patients were analyzed. A graded item response theory (IRT) model was fitted to the cross-sectional data. Short-form scales with three items were aimed for, by selecting items with best fit according to the IRT model, avoiding cross-culturally noninvariant items. Seven scales measuring mental and social well-being and function as well as one overall QoL impact item were analyzed in a bifactor model, to develop a supplementary composite score. Short-form scales were linked to original scales with IRT-based summed-score-linking. Agreement between the short and long form was estimated by agreement plots, intraclass correlations, and mean score levels. Responsiveness was compared by relative validity indices, clinical validity by ability to detect clinically relevant differences, and test-retest reliability by intra-class correlation.

RESULTS

One four-item scale was not abbreviated and one two-item scale was omitted from the short-form. For the 11 scales undergoing abbreviation, 10 with three and one with four items were developed. A bifactor model with good overall fit was fitted to the composite score, including the single QoL item. Responsiveness and clinical validity of the short-form scales were preserved, as were test-retest reliability (0.75-0.89). Short- versus long-form intraclass correlations were high (0.89-0.98), and the mean scale levels were similar.

CONCLUSIONS

A 39-item version of the ThyPRO, with good measurement properties, was developed and is recommended for clinical use.