Validity and reliability of acoustic analysis of respiratory sounds in infants

Objective: To investigate the validity and reliability of computerised acoustic analysis in the detection of abnormal respiratory noises in infants. Methods: Blinded, prospective comparison of acoustic analysis with stethoscope examination. Validity and reliability of acoustic analysis were assessed by calculating the degree of observer agreement using the κ statistic with 95% confidence intervals (CI). Results: 102 infants under 18 months were recruited. Convergent validity for agreement between stethoscope examination and acoustic analysis was poor for wheeze (κ = 0.07 (95% CI, –0.13 to 0.26)) and rattles (κ = 0.11 (–0.05 to 0.27)) and fair for crackles (κ = 0.36 (0.18 to 0.54)). Both the stethoscope and acoustic analysis distinguished well between sounds (discriminant validity). Agreement between observers for the presence of wheeze was poor for both stethoscope examination and acoustic analysis. Agreement for rattles was moderate for the stethoscope but poor for acoustic analysis. Agreement for crackles was moderate using both techniques. Within-observer reliability for all sounds using acoustic analysis was moderate to good. Conclusions: The stethoscope is unreliable for assessing respiratory sounds in infants. This has important implications for its use as a diagnostic tool for lung disorders in infants, and confirms that it cannot be used as a gold standard. Because of the unreliability of the stethoscope, the validity of acoustic analysis could not be demonstrated, although it could discriminate between sounds well and showed good within-observer reliability. For acoustic analysis, targeted training and the development of computerised pattern recognition systems may improve reliability so that it can be used in clinical practice.     

Are bedside features of shock reproducible between different observers?

Shock is often under-reported in children attending hospitals in developing countries. Readily obtainable features of shock (capillary refill time, temperature gradient, pulse volume, and signs of dehydration) are widely used to help prioritise management in the emergency assessment of critically ill or injured children. However, data are lacking on their validity, including, importantly, reproducibility between observers. Agreement of these signs was examined in 100 consecutive children admitted to a paediatric ward on the coast of Kenya. After an initial training of clinical sign recognition, there was moderate agreement for most features of cardiovascular compromise (delayed capillary refill > or =4 s, kappa = 0.49; and weak pulse volume, kappa = 0.4) and only substantial agreement for temperature gradient (kappa = 0.62). For hydration status, only in the assessment of skin turgor was there a moderate level of agreement (kappa = 0.55). Capillary refill times and assessment of pulse volume recommended by the recent American consensus guidelines achieved only a "low" moderate to poor interrater agreement, questioning the reliability of such parameters.     

Interexaminer reliability in physical examination of pediatric patients with abdominal pain

OBJECTIVE: To test the interexaminer reliability of abdominal examinations performed by pediatric emergency medicine physicians and surgeons in an emergency department. METHODS: A prospective cross-sectional study in which 3 different types of physicians (pediatric emergency department residents, pediatric emergency department attending physicians, and pediatric surgeons in training) independently examined a convenience sample of children (aged 3-19 years) with initial complaint of abdominal pain. The interexaminer reliability of 6 components of the abdominal examination (the presence or absence of abdominal distension, abdominal tenderness to percussion, abdominal tenderness to palpation, abdominal guarding, rebound tenderness, and bowel sounds) and the clinical diagnosis of peritonitis was tested. RESULTS: Sixty-eight patients were examined by pediatric emergency department residents and pediatric emergency department attending physicians. All 3 physician types examined 46 of these 68 patients. When comparing residents and attending physicians, the components of the abdominal examination showed less than moderate chance-adjusted agreement (kappa range, -0.04 to 0.38). When comparing attending physicians and surgeons, the presence of rebound tenderness showed moderate agreement (kappa = 0.54). The rest of the components demonstrated less than moderate chance-adjusted agreement (kappa range, -0.04 to 0.34). CONCLUSIONS: The components of the abdominal examination are poorly reliable between physician types. Only the "rebound tenderness" component of the abdominal examination shows moderate agreement between the pediatric emergency department attending physicians and the surgeon. No component of the abdominal examination appears to be consistently reliable. Interexaminer agreement must be considered when developing management strategies for acute abdomen. Interventions to improve reliability should be developed.     

Differential response of wheezes and ruttles to anticholinergics.

Computerised breath sounds analysis was used to assess the response of infants with wheeze and ruttles to the drug ipratropium bromide. A mean decrease in breath sounds intensity occurred in infants with ruttles after five minutes (20.5 dB), but not until 20 minutes in those with wheeze (8.1 dB). This differential response may be related to different underlying pathophysiology.     

Differential response of wheezes and ruttles to anticholinergics

Computerised breath sounds analysis was used to assess the response of infants with wheeze and ruttles to the drug ipratropium bromide. A mean decrease in breath sounds intensity occurred in infants with ruttles after five minutes (20.5 dB), but not until 20 minutes in those with wheeze (8.1 dB). This differential response may be related to different underlying pathophysiology.     

Parents' interpretations of children's respiratory symptoms on video.

AIMS: To investigate how parents report children's respiratory sounds on video compared to a clinical "gold standard". METHODS: Five clinicians agreed on 10 video clips of children with audible breathing. These responses were the "gold standard". The clips were shown to parents of children: (a) with asthma/wheeze; (b) with other respiratory complaints; (c) without respiratory complaints. Parents were asked what they called the sounds, where they originated, and whether their own child made similar sounds. RESULTS: A total of 190 parents took part. The "correct" labelling of wheeze was 59% (95% confidence interval 52 to 66%) and 47% (95% confidence interval 40 to 54%) for other sounds (stridor, snoring, stertor). Parents were better at locating both sounds than labelling. There were no differences between subject groups. There were more false positive responses to labelling and locating other sounds than for wheeze (27% v 8% and 33% v 10%). CONCLUSION: Parents locate sounds better than describing them. At least 30% of all parents use other words for wheeze and 30% labelled other sounds as "wheeze". This could have important clinical implications.     

Inter-observer reliability of the “Assessment of Motor Repertoire — 3 to 5 Months” based on video recordings of infants

Objective

A detailed analysis of infant motor behaviour can show up indicators for later neurological impairment. The “Assessment of Motor Repertoire — 3 to 5 Months”, which is part of Prechtl's general movement assessment, could potentially be used for this purpose. The aim of the present study was to investigate inter-observer reliability in this instrument.

Method

Video recordings of 24 infants (corrected ages 3 to 5 months, gestational ages 24 to 42 weeks) were analysed by four observers. Kappa and ICC statistics were applied in the reliability analysis.

Results

High to very high inter-observer reliability was found in the assessment of “Fidgety Movements” (kappa 0.75-0.91). Agreement on the “Movement Character” was also high (kappa 0.54-0.84), while the assessment of the “Posture” showed the lowest inter-observer reliability (kappa 0.39-0.56). Moderate to high inter-observer reliability (kappa 0.51-0.84) was achieved in the field “Quality of Other Movements”, and moderate in “Repertoire of Co-Existent Other Movements” (kappa 0.51-0.69).Inter-observer reliability in the assessment of the total “Motor Optimality Score” was very high between all four observers as intraclass correlation coefficient (2,1) was 0.87, and ICCs for the pairwise analyses ranged between 0.80 and 0.94.

Conclusion

Inter-observer reliability in the “Assessment of Motor Repertoire — 3 to 5 Months” was satisfactory in respect of the subcategories and in case of high and low total optimality scores in pairwise assessments. In the total optimality scores, however, there was some inconsistency in the middle range of the scale.     

Development and initial validation of the EDIN scale, a new tool for assessing prolonged pain in preterm infants.

OBJECTIVE: To develop and validate a scale suitable for use in clinical practice as a tool for assessing prolonged pain in premature infants. METHODS: Pain indicators identified by observation of preterm infants and selected by a panel of experts were used to develop the EDIN scale (Echelle Douleur Inconfort Nouveau-Né, neonatal pain and discomfort scale). A cohort of preterm infants was studied prospectively to determine construct validity, inter-rater reliability, and internal consistency of the scale. RESULTS: The EDIN scale uses five behavioural indicators of prolonged pain: facial activity, body movements, quality of sleep, quality of contact with nurses, and consolability. The validation study included 76 preterm infants with a mean gestational age of 31.5 weeks. Inter-rater reliability was acceptable, with a kappa coefficient range of 0.59-0.74. Internal consistency was high: Cronbach's alpha coefficients calculated after deleting each item ranged from 0.86 to 0.94. To establish construct validity, EDIN scores in two extreme situations (pain and no pain) were compared, and a significant difference was observed. CONCLUSIONS: The validation data suggest that the EDIN is appropriate for assessing prolonged pain in preterm infants. Further studies are warranted to obtain further evidence of construct validity by comparing scores in less extreme situations.     

A parent-completed respiratory questionnaire for 1-year-old children: repeatability.

BACKGROUND AND AIMS: There are few standardised questionnaires for the assessment of respiratory symptoms in preschool children. We have developed and tested the short-term repeatability of a postal questionnaire on respiratory symptoms for 1-year-old children. METHODS: A newly developed postal questionnaire for the assessment of wheeze and other respiratory symptoms was sent to parents of a population-based random sample of 4300 children aged 12-24 months. After an interval of 3 months, a random sample of 800 respondents received the questionnaire a second time. The responses were compared using Cohen's kappa (kappa) to assess agreement corrected for chance. RESULTS: The first questionnaire was returned by 3194 (74%) families, the second one by 460/800 (58%). Repeatability was excellent (kappa 0.80-0.96) for questions on household characteristics, environmental exposures and family history, good (kappa 0.61-0.80) for questions on prevalence, severity and treatment of wheeze, and moderate (kappa 0.39-0.66) for chronic cough and upper respiratory symptoms. CONCLUSIONS: This short postal questionnaire designed for use in population-based studies has excellent repeatability for family and household characteristics and good repeatability for questions on wheeze. Short-term changes in symptom status might be responsible for variable answers on recent chronic cough and upper respiratory symptoms. Overall, the questionnaire is a valuable instrument for community-based research on respiratory symptoms in 1 to 2-year-old children.     

Development and validation of the ABC pain scale for healthy full-term babies

AIM: We developed and validated a pain scale (ABC scale) for term babies based on acoustic features of crying. METHODS: The scale consisted of three different cry parameters: (a) pitch of the first cry; (b) rhythmicity of the crying bout; (c) constancy of crying intensity. These parameters were previously found to distinguish between medium and high levels of pain measured by spectral analysis of crying. We validated the scale using healthy term babies undergoing routine heel prick. Concurrent validity was assessed comparing pain values obtained with our scale with those obtained with another pain scale; this relationship was also used to assess the sensitivity of the scale. To assess specificity we compared the ABC scores during a painful event (heel prick) with two non-painful events (preliminary phase of prick in the same group of babies, and heel prick with analgesia in another group). RESULTS: Specificity: (a) analgesic/non-analgesic comparison, p < 0.0001; (b) pain/sham comparison, p < 0.0001). Sensitivity: a high correlation between scores of the ABC scale and the Douleur Aigue du Nouveau-Né scale indicates good sensitivity. Concurrent validity: Spearman rho = 0.91. Internal consistency: Cronbach's alpha = 0.76. Inter-rater reliability: Cohen's kappa for multiple raters = 0.83. Intra-rater reliability: Cohen's kappa = 0.85. Practicality: All nurses who used it scored the scale as "good". CONCLUSION: The ABC scale proved to be simple and reliable for assessing pain in healthy, non-intubated term newborns.     

Reliability of the Neonatal Neurobehavioral Examination — Chinese version

A Chinese version of the Neonatal Neurobehavioral Examination (NNE-C) was applied to 15 high-risk infants and five normal term infants for investigation of reliability. The infants were assessed by three physical therapists to examine inter-rater reliability and reassessed by one of the therapists within 2 days to examine test-retest reproducibility. The internal consistency of the NNE-C scale was high, with an alpha coefficient of 0.84. The inter-rater reliability was high for item scores (kappa coefficients > 0.75 for 81% of the items) and for section and total scores (all intraclass correlation coefficients > 0.80). The test-retest reproducibility was moderate for item scores (kappa coefficients > 0.40 for 85% of the items) and was high for section and total scores (all intraclass correlation coefficients > 0.80). We conclude that the NNE-C scale is clinically feasible and reliable for the evaluation of neurobehavioral functions of high-risk and normal term infants in Chinese-speaking societies.     

Parents' interpretations of children's respiratory symptoms on video

AIMS—To investigate how parents report children''s respiratory sounds on video compared to a clinical "gold standard".METHODS—Five clinicians agreed on 10 video clips of children with audible breathing. These responses were the "gold standard". The clips were shown to parents of children: (a) with asthma/wheeze; (b) with other respiratory complaints; (c) without respiratory complaints. Parents were asked what they called the sounds, where they originated, and whether their own child made similar sounds.RESULTS—A total of 190 parents took part. The "correct" labelling of wheeze was 59% (95% confidence interval 52 to 66%) and 47% (95% confidence interval 40 to 54%) for other sounds (stridor, snoring, stertor). Parents were better at locating both sounds than labelling. There were no differences between subject groups. There were more false positive responses to labelling and locating other sounds than for wheeze (27% v 8% and 33% v 10%).CONCLUSION—Parents locate sounds better than describing them. At least 30% of all parents use other words for wheeze and 30% labelled other sounds as "wheeze". This could have important clinical implications.     

Validity of the fine motor area of the 12-month ages and stages questionnaire in infants following major surgery

The Ages and Stages Questionnaires (ASQ) are parent-report screening tools to identify infants at risk of developmental difficulties. The purpose of this study was to examine validity and internal reliability of the fine motor developmental area of the ASQ, 2nd edition (ASQ2-FM) for screening 12-month-old infants following major surgery. The ASQ2-FM was completed by caregivers of 74 infants who had cardiac surgery in the first 90 days of life, 104 infants who had noncardiac surgery in the first 90 days of life, and a control group of 154 infants. The Rasch item response analysis revealed that the ASQ2-FM had poor ability to discriminate among levels of fine motor ability. Sensitivity was poor (20%) and specificity was good (98%) when compared with the scores for the fine motor subscale of the Bayley Scales of Infant and Toddler Development. The ASQ2-FM under-identified infants at risk for fine motor delay; internal reliability and construct validity do not support use as a screening tool of fine motor development of infants aged 12 months who have undergone major surgery.     

Test–retest, inter-assessor and intra-assessor reliability of the modified Touwen examination

Interest in the Touwen examination (1979) for the assessment of minor neurological dysfunction (MND) is growing. However, information on psychometric properties of this assessment is scarce. Therefore the present study aimed at assessing the test's test-retest, inter- and intra-assessor reliability. Eleven boys and 14 girls, visiting a mainstream school, aged 4-12 years, were tested neurologically by 3 investigators. Inter- and intra-assessor reliability were based on videotapes of the assessments. To determine test-retest reliability children were re-assessed after about 1 month. The various forms of reliability were calculated for neurological classification (normal, simple MND, complex MND), clusters of dysfunction and single items. Twelve girls and 7 boys showed a normal neurological condition; 2 girls and 1 boy were classified as having simple MND and 3 boys as having complex MND. The 3 forms of reliability for neurological classification were good (kappa=0.71-0.83). Reliability for the majority of cluster scores was good. Test-retest agreement was moderate for the clusters reflexes and coordination and poor for fine manipulation; inter-assessor agreement was moderate for the clusters coordination and fine manipulation; intra-assessor agreement moderate for fine manipulation. Reliability for the majority of items was good. In conclusion, the Touwen examination has a moderate to good reliability when applied in a relatively healthy population. Whether reliability is similarly good in populations of children with minor developmental disorders has to be determined.     

Heart murmurs recorded by a sensor based electronic stethoscope and e-mailed for remote assessment.

BACKGROUND: Heart murmurs are common in children, and they are often referred to a specialist for examination. A clinically innocent murmur does not need further investigation. The referral area of the University Hospital is large and sparsely populated. A new service for remote auscultation (telemedicine) of heart murmurs in children was established where heart sounds and short texts were sent as an attachment to e-mails. AIM: To assess the clinical quality of this method. METHODS: Heart sounds from 47 patients with no murmur (n = 7), with innocent murmurs (n = 20), or with pathological murmurs (n = 20) were recorded using a sensor based stethoscope and e-mailed to a remote computer. The sounds were repeated, giving 100 cases that were randomly distributed on a compact disc. Four cardiologists assessed and categorised the cases as having "no murmur", "innocent murmur", or "pathological murmur", recorded the assessment time per case, their degree of certainty, and whether they recommended referral. RESULTS: On average, 2.1 minutes were spent on each case. The mean sensitivity and specificity were 89.7% and 98.2% respectively, and the inter-observer and intra-observer variabilities were low (kappa 0.81 and 0.87), respectively. A total of 93.4% of cases with a pathological murmur and 12.6% of cases with an innocent murmur were recommended for referral. CONCLUSION: Telemedical referral of patients with heart murmurs for remote assessment by a cardiologist is safe and saves time. Skilled auscultation is adequate to detect patients with innocent murmurs.     

Validity of the Fine Motor Area of the 12-Month Ages and Stages Questionnaire in Infants Following Major Surgery

ABSTRACT

The Ages and Stages Questionnaires (ASQ) are parent-report screening tools to identify infants at risk of developmental difficulties. The purpose of this study was to examine validity and internal reliability of the fine motor developmental area of the ASQ, 2nd edition (ASQ2-FM) for screening 12-month-old infants following major surgery. The ASQ2-FM was completed by caregivers of 74 infants who had cardiac surgery in the first 90 days of life, 104 infants who had noncardiac surgery in the first 90 days of life, and a control group of 154 infants. The Rasch item response analysis revealed that the ASQ2-FM had poor ability to discriminate among levels of fine motor ability. Sensitivity was poor (20%) and specificity was good (98%) when compared with the scores for the fine motor subscale of the Bayley Scales of Infant and Toddler Development. The ASQ2-FM under-identified infants at risk for fine motor delay; internal reliability and construct validity do not support use as a screening tool of fine motor development of infants aged 12 months who have undergone major surgery.     

Evaluation of an asthma severity score

Objective : To evaluate inter-observer agreement and validity of an asthma severity score derived from wheeze, heart rate and accessory muscle use components.
Methodology : Children with acute asthma were examined independently and simultaneously by two observers, followed by pulse oximetry and spirometry in those over 5 years with repeatable measurements.
Results : Inter-observer agreement was very good (weighted kappa 0.82, 95% confidence interval 0.63 to 1.00). the component with the best agreement being the accessory muscle score (0.76, 0.57 to 0.95).
The score correlated significantly with oxygen saturation, heart rate, and forced expiratory volume in 1 s (FEV1). In a multivariate model, FEV1 was best related to accessory muscle use.
Conclusions : The asthma severity score has very good inter-observer agreement with a moderate relationship to oxygenation and FEV1.     

New Ballard Score, expanded to include extremely premature infants

The Ballard Maturational Score was refined and expanded to achieve greater accuracy and to include extremely premature neonates. To test validity, accuracy, interrater reliability, and optimal postnatal age at examination, the resulting New Ballard Score (NBS) was assessed for 578 newly born infants and the results were analyzed. Gestational ages ranged from 20 to 44 weeks and postnatal ages at examination ranged from birth to 96 hours. In 530 infants, gestational age by last menstrual period was confirmed by agreement within 2 weeks with gestational age by prenatal ultrasonography (C-GLMP). For these infants, correlation between gestational age by NBS and C-GLMP was 0.97. Mean differences between gestational age by NBS and C-GLMP were 0.32 +/- 1.58 weeks and 0.15 +/- 1.46 weeks among the extremely premature infants (less than 26 weeks) and among the total population, respectively. Correlations between the individual criteria and C-GLMP ranged from 0.72 to 0.82. Interrater reliability of NBS, as determined by correlation between raters who rated the same subgroup of infants, ws 0.95. For infants less than 26 weeks of gestational age, the greatest validity (97% within 2 weeks of C-GLMP) was seen when the examination was performed before 12 hours of postnatal age. For infants at least 26 weeks of gestational age, percentages of agreement with C-GLMP remained constant, averaging 92% for all postnatal age categories up to 96 hours. The NBS is a valid and accurate gestational assessment tool for extremely premature infants and remains valid for the entire newborn infant population.     

Safety of budesonide inhalation suspension in infants aged six to twelve months with mild to moderate persistent asthma or recurrent wheeze

OBJECTIVE: To compare the safety of budesonide inhalation suspension (BIS) with placebo in infants 6 to 12 months of age with mild to moderate persistent asthma or recurrent wheeze. STUDY DESIGN: In this multicenter, randomized, double-blinded, parallel-group, placebo-controlled study, 141 patients received 0.5 mg BIS (n = 48), 1.0 mg BIS (n = 44), or placebo (n = 49) once daily for 12 weeks. The primary variable was adrenal function, based on cosyntropin-stimulated plasma cortisol levels. Spontaneous adverse events and clinical laboratory findings also were monitored. RESULTS: Overall, the types and frequencies of adverse events reported during the study were comparable across treatment groups. The response to cosyntropin stimulation was similar across treatment groups, with no significant difference between BIS treatment and placebo. CONCLUSIONS: The safety profile of BIS was similar to that of placebo, with no suppressive effect on adrenal function in patients 6 to 12 months of age with mild to moderate persistent asthma or recurrent wheeze.