Transforming Integrated Care Through Co-production: A Systematic Review Using Meta-ethnography.

Introduction: There is a requirement for health and care systems and services to work on an equitable basis with people who use and provide integrated care. In response, co-production has become essential in the design and transformation of services. Globally, an array of approaches have been implemented to achieve this. This unique review explores multi-context and multi-method examples of co-production in integrated care using an exceptional combination of methods. Aim: To review and synthesise evidence that examines how co-production with service users, unpaid carers and members of staff can affect the design and transformation of integrated care services. Methods: Systematic review using meta-ethnography with input from a patient and public involvement (PPI) co-production advisory group. Meta-ethnography can generate theories by interpreting patterns between studies set in different contexts. Nine academic and four grey literature databases were searched for publications between 2012-2022. Data were extracted, analysed, translated and interpreted using the seven phases of meta-ethnography and PPI. Findings: A total of 2,097 studies were identified. 10 met the inclusion criteria. Studies demonstrated a variety of integrated care provisions for diverse populations. Co-production was most successful through person-centred design, innovative planning, and collaboration. Key impacts on service transformation were structural changes, accessibility, and acceptability of service delivery. The methods applied organically drew out new interpretations, namely a novel cyclic framework for application within integrated care. Conclusion: Effective co-production requires a process with a well-defined focus. Implementing co-delivery, with peer support, facilitates service user involvement to be embedded at a higher level on the 'ladder of co-production'. An additional step on the ladder is proposed; a cyclic co-delivery framework. This innovative and operational development has potential to enable better-sustained person-centred integrated care services.

Trends in Long-Term Ventilation Care in U.K. Children and Young People-Further Consideration Required for Pediatric Critical Care Services.

OBJECTIVES: The objective was to compare specific data from the 2020 National Confidential Enquiry into Patient Outcome and Death (NCEPOD) report "Balancing the Pressures" with two previous U.K. studies and to examine changes in the pediatric population requiring long-term ventilation (LTV) as well as the types delivered. We believe that the new data presented will facilitate future service planning. DESIGN: A subset of confidential enquiry data derived from a study by a nationally funded quality improvement organization (NCEPOD: www.ncepod.org.uk ) was compared with two previous U.K. datasets. SETTING: Healthcare providers across England, Wales, and Northern Ireland-inpatient and community settings. PATIENTS: Children and young people (CAYP) 0-16 years old receiving LTV between April 1, 2016, and March 31, 2018. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: When comparing the NCEPOD data with that last published in the United Kingdom, the number of CAYP requiring LTV more than doubled between 2008 and 2018 (933-2,093). There has also been a particular increase in the proportion of children that were under two when they were commenced on LTV (26-39.2%). Children are now more likely than previously to be receiving LTV to manage upper airway obstruction and CNS conditions. There has also been an approximate doubling of those receiving LTV over the whole 24-hour period (9.4-18.4%). CONCLUSIONS: The increased numbers and changing characteristics of babies and children requiring LTV over the last 3 decades in the United Kingdom have implications for all healthcare sectors but particularly for providers of critical care services.

Effects of changes in short-term human cognition on reported healthcare utilisation.

Growing empirical evidence indicates that financial anxiety causes reductions in short-term cognitive capacity. Results from urban communities in Delhi, India show sizable differences in the number of health events recalled between the poor and non-poor respondents over experimentally controlled recall periods. One explanation for this recall difference is 'poor memory'. Such results provide additional reasons for healthy skepticism of the accuracy of self-reported health survey data. The present research identifies which forms of cognitive capacity are related to health event recall and assesses the roles of poverty and illiteracy as mediating variables. Results indicate that underreporting of health events among the poor in rural Kenya is not solely due to 'poor memory'. Data used comes from a repeated cross-sectional study conducted in Samburu county, Kenya over 10-months between 2017-2018. This period coincided with the ending of a protracted and severe drought in East Africa. The results presented in the current study confirm the poor and non-poor distinction, but provide a more detailed cognitive explanation for such results. Reflective throught, as measured by fluid intelligence and heuristic use, is shown to be good predictors of fever recall among relatively poor rura communities in central Kenya.

Reference equations for tidal breathing parameters using structured light plethysmography.

Tidal breathing measurements can be used to identify changes in respiratory status. Structured light plethysmography (SLP) is a non-contact tidal breathing measurement technique. Lack of reference equations for SLP parameters makes clinical decision-making difficult. We have developed a set of growth-adjusted reference equations for seven clinically pertinent parameters of respiratory rate (f R), inspiratory time (t I), expiratory time (t E), duty cycle (t I/total breath time), phase (thoraco-abdominal asynchrony (TAA)), relative thoracic contribution (RTC) and tidal inspiratory/expiratory flow at 50% volume (IE50). Reference equations were developed based on a cohort of 198 seated healthy subjects (age 2-75 years, height 82-194 cm, 108 males). We adopted the same methodological approach as the Global Lung Function Initiative (GLI) report on spirometric reference equations. 5 min of tidal breathing was recorded per subject. Parameters were summarised with their medians. The supplementary material provided is an integral part of this work and a reference range calculator is provided therein. We found predicted f R to decrease with age and height rapidly in the first 20 years and slowly thereafter. Expected t I, t E and RTC followed the opposite trend. RTC was 6.7% higher in females. Duty cycle increased with age, peaked at 13 years and decreased thereafter. TAA was high and variable in early life and declined rapidly with age. Predicted IE50 was constant, as it did not correlate with growth. These reference ranges for seven key measures ensure that clinicians and researchers can identify tidal breathing patterns in disease and better understand and interpret SLP and tidal breathing data.

Comparison of forced oscillation technique and spirometry in paediatric asthma.

Evaluation of airway obstruction with forced oscillation technique can be an adjunct to spirometry or even used as a primary method in those children unable to perform spirometry https://bit.ly/34rE6x2.

The role of short-term changes in cognitive capacity on economic expenditure among Kenyan agro-pastoralists.

The increased exposure of pastoralist communities in East Africa to climatic shocks has focused attention on the resilience of these communities. Although many social scientists directly or indirectly infer versions of homo-economic agents, increasing evidence in development behavioral economics, indicates that such assumptions may be misplaced. Despite on-going advances in the science concerning the effects of stress on dynamic changes in short-term cognitive capacity, there remains limited understanding of the effects of changes in cognitive capacity on economic decision making. The present research empirically evaluates the drivers of short-term changes in cognitive capacity-cognitive ability and heuristic use-and its effect on crop and livestock expenditure among predominantly poor Kenyan agro-pastoralists. Three rounds of cognition and survey data from Samburu, Kenya is analysed. The primary data was collected at the end of the 2015-16 East African drought and covers an 11-month period between October 2016 and September 2017. Dynamic panel estimation, employing maximum likelihood, is used on balanced and unbalanced data. Results indicate that fluid intelligence and heuristic use, along with literacy and stressors, affect crop expenditure. Perceptions of scarcity, relative to prior expectations, are also identified as an important determinant of short-term changes in cognitive ability. These results underscore the importance of better understanding the effects of short-term changes in cognitive capacity on economic expenditure among the poor.

Variable Cognition in ABM Decision-Making: An Application to Livestock Vaccine Choice.

Modeling realistic human decision-making is an important feature of good policy design processes. The use of an agent-based modeling framework allows for quantitative human decision-models that assume fully rational agents. This research introduces a dynamic human decision-making sub-model. The parameterisation of human memory and "rationality" in a decision-making model represents an important extension of decision-making in ABMs. A data driven model of herd movement within a dynamic natural environment is the context for evaluating the cognitive decision-making model. The natural and human environments are linked via memory and rationality that affect herdsmen decision-making to vaccinate cattle using a once-for-life vaccine (Rift Valley fever) and an annual booster vaccine (Contagious Bovine Pleuropneumonia). The simulation model uses environmental data from Samburu county, Kenya from 2004 to 2015. The cognitive parameters of memory and "rationality" are shown to successfully differentiate between vaccination decisions that are characterized by annual and once-for-life choices. The preliminary specifications and findings from the dynamic cognition-pastoralist agent-based model (PastoralScape) indicate that the model offers much to livestock vaccination modeling among small-scale herders.

Investigating the nature of competition facing private healthcare facilities: the case of maternity care in Uttar Pradesh, India.

The private healthcare sector in low- and middle-income countries is increasingly seen as of public health importance, with widespread interest in improving private provider engagement. However, there is relatively little literature providing an in-depth understanding of the operation of private providers. We conducted a mixed methods analysis of the nature of competition faced by private delivery providers in Uttar Pradesh, India, where maternal mortality remains very high. We mapped health facilities in five contrasting districts, surveyed private facilities providing deliveries and conducted in-depth interviews with facility staff, allied providers (e.g. ambulance drivers, pathology laboratories) and other key informants. Over 3800 private facilities were mapped, of which 8% reported providing deliveries, mostly clustered in cities and larger towns. 89% of delivery facilities provided C-sections, but over half were not registered. Facilities were generally small, and the majority were independently owned, mostly by medical doctors and, to a lesser extent, AYUSH (non-biomedical) providers and others without formal qualifications. Recent growth in facility numbers had led to intense competition, particularly among mid-level facilities where customers were more price sensitive. In all facilities, nearly all payment was out-of-pocket, with very low-insurance coverage. Non-price competition was a key feature of the market and included location (preferably on highways or close to government facilities), medical infrastructure, hotel features, staff qualifications and reputation, and marketing. There was heavy reliance on visiting consultants such as obstetricians, surgeons and anaesthetists, and payment of hefty commission payments to agents who brought clients to the facility, for both new patients and those transferring from public facilities. Building on these insights, strategies for private sector engagement could include a foundation of universal facility registration, adaptation of accreditation schemes to lower-level facilities, improved third-party payment mechanisms and strategic purchasing, and enhanced patient information on facility availability, costs and quality.

Information sharing and willingness-to-pay for CBPP vaccine in rural Kenya.

The study estimates cattle owners' willingness-to-pay (WTP) for Contagious Bovine Pleuropneumonia (CBPP) vaccine in Samburu county, Kenya. Of particular policy relevance, the study presents findings on WTP for i) improved access to vaccines and ii) timely access to disease-risk information. The mean price for a CBPP vaccine was estimated at KES 66 (USD 0.64). This price relates to a CBPP vaccine that requires a 1.8 h commute, cattle owners' receipt of timely information that the CBPP disease risk is low-moderate and the vaccine lowers the risk of either tail-drop or post-vaccine abortion. The conditional WTP for mean travel duration and high-risk information are similar at KES 53.9 and KES 51.5. The marginal effect on demand for a 1 h additional travel duration and provision of CBPP disease risk information was estimated as a 1.5 per cent reduction and 2.3 increase. The results of this study indicate that cattle owners value greater levels of knowledge concerning the changing risk profile of CBPP in their community and improved access to CBPP vaccination services. Enhanced engagement with cattle owners concerning CBPP would likely result in a greater utilisation of available CBPP vaccines, conditional on the perceived CBPP disease risk.

Government doctor absenteeism and its effects on consumer demand in rural north India.

Government doctor absenteeism from their public posts is a sizable problem across developing economies. The consumer demand estimation for outpatient fever treatment presented in this paper investigates the interrelationship between government doctor absenteeism and the large informal healthcare sector. Using a counterfactual framework, this paper estimates treatment effect of eliminating government doctor absenteeism. The effects are measured by changes to the market share of government Bachelor of Medicine and Bachelor of Surgery (MBBS) providers and resulting own-price elasticities of demand for government MBBS providers and unqualified providers. Modelling incorporates patients expected health outcomes by provider via the use of a qualitative measure of word-of-mouth recommendations. Results indicate that eliminating government MBBS provider absenteeism in North India would increase utilisation of government outpatient fever treatments from 18% to 50%.

Informal healthcare sector and marginalized groups: Repeat visits in rural North India.

The interrelationship between the public and private sectors, and formal and informal healthcare sectors effects market-level service quality, pricing behaviour and referral networks. However, health utilisation analysis of national survey data from many low and middle income countries is constrained by the lack of disaggregated health provider data. This study is concerned with the pattern of repeat outpatient consultations for a single episode of fever from public and private qualified providers and private unqualified providers. Cross-sectional survey data from 1173 adult respondents sampled from three districts within India's most populous state-Uttar Pradesh is analysed. Data was collected during the monsoon season-September to October-in 2012. Regression analysis focuses on the pattern of repeats visits for a single episode of mild-sever fever as the dependent variable. Results show that Women and Muslims in rural north India are more likely to not access healthcare, and if they do, consult with low quality unqualified outpatient healthcare providers. For fever durations of four or more days, men are more likely to access unqualified providers compared to women. Results of the current study supports the literature that women's utilisation of outpatient healthcare for communicable illnesses in LMICs is often less than men. A relative lack of access to household resources explains why fever duration parameter estimates for women and men differ.

Tidal breathing parameters measured by structured light plethysmography in children aged 2-12 years recovering from acute asthma/wheeze compared with healthy children.

Measurement of lung function can be difficult in young children. Structured light plethysmography (SLP) is a novel, noncontact method of measuring tidal breathing that monitors displacement of the thoraco-abdominal wall. SLP was used to compare breathing in children recovering from an acute exacerbation of asthma/wheeze and an age-matched cohort of controls. Children aged 2-12 years with acute asthma/wheeze (n = 39) underwent two 5-min SLP assessments, one before bronchodilator treatment and one after. SLP was performed once in controls (n = 54). Nonparametric comparisons of patients to healthy children and of pre-bronchodilator to post-bronchodilator were made for all children, and also stratified by age group (2-5 vs. 6-12 years old). In the asthma/wheeze group, IE50SLP (inspiratory to expiratory flow ratio) was higher (median 1.47 vs. 1.31; P = 0.002), thoraco-abdominal asynchrony (TAA) and left-right asynchrony were greater (both P < 0.001), and respiratory rate was faster (P < 0.001) than in controls. All other timing indices were shorter and displayed reduced variability (all P < 0.001). Variability in time to peak inspiratory flow was also reduced (P < 0.001). Younger children showed a greater effect than older children for TAA (interaction P < 0.05). After bronchodilator treatment, the overall cohort showed a reduction in within-subject variability in time to peak expiratory flow only (P < 0.001). Younger children exhibited a reduction in relative contribution of the thorax, TAA, and variability in TAA (interaction P < 0.05). SLP can be successfully performed in young children. The potential of SLP to monitor diseases such as asthma in children is worthy of further investigation. ClinicalTrials.gov identifier: NCT02543333.

Tidal breathing parameters measured using structured light plethysmography in healthy children and those with asthma before and after bronchodilator.

Structured light plethysmography (SLP) is a light-based, noncontact technique that measures tidal breathing by monitoring displacements of the thoracoabdominal (TA) wall. We used SLP to measure tidal breathing parameters and their within-subject variability (v) in 30 children aged 7-16 years with asthma and abnormal spirometry (forced expiratory volume in 1 sec [FEV1] <80% predicted) during a routine clinic appointment. As part of standard care, the reversibility of airway obstruction was assessed by repeating spirometry after administration of an inhaled bronchodilator. In this study, SLP was performed before and after bronchodilator administration, and also once in 41 age-matched controls. In the asthma group, there was a significant increase in spirometry-assessed mean FEV1 after administration of bronchodilator. Of all measured tidal breathing parameters, the most informative was the inspiratory to expiratory TA displacement ratio (IE50SLP, calculated as TIF50SLP/TEF50SLP, where TIF50SLP is tidal inspiratory TA displacement rate at 50% of inspiratory displacement and TEF50SLP is tidal expiratory TA displacement rate at 50% of expiratory displacement). Median (m) IE50SLP and its variability (vIE50SLP) were both higher in children with asthma (prebronchodilator) compared with healthy children (mIE50SLP: 1.53 vs. 1.22, P < 0.001; vIE50SLP: 0.63 vs. 0.47, P < 0.001). After administration of bronchodilators to the asthma group, mIE50SLP decreased from 1.53 to 1.45 (P = 0.01) and vIE50SLP decreased from 0.63 to 0.60 (P = 0.04). SLP-measured tidal breathing parameters could differentiate between children with and without asthma and indicate a response to bronchodilator.

Evaluation of the agreement of tidal breathing parameters measured simultaneously using pneumotachography and structured light plethysmography.

Structured light plethysmography (SLP) is a noncontact, noninvasive, respiratory measurement technique, which uses a structured pattern of light and two cameras to track displacement of the thoraco-abdominal wall during tidal breathing. The primary objective of this study was to examine agreement between tidal breathing parameters measured simultaneously for 45 sec using pneumotachography and SLP in a group of 20 participants with a range of respiratory patterns ("primary cohort"). To examine repeatability of the agreement, an additional 21 healthy subjects ("repeatability cohort") were measured twice during resting breathing and once during increased respiratory rate (RR). Breath-by-breath and averaged RR, inspiratory time (tI), expiratory time (tE), total breath time (tTot), tI/tE, tI/tTot, and IE50 (inspiratory to expiratory flow measured at 50% of tidal volume) were calculated. Bland-Altman plots were used to assess the agreement. In the primary cohort, breath-by-breath agreement for RR was ±1.44 breaths per minute (brpm). tI, tE, and tTot agreed to ±0.22, ±0.29, and ±0.32 sec, respectively, and tI/tE, tI/tTot, and IE50/IE50SLP to ±0.16, ±0.05, and ±0.55, respectively. When averaged, agreement for RR was ±0.19 brpm. tI, tE, and tTot were within ±0.16, ±0.16, and ±0.07 sec, respectively, and tI/tE, tI/tTot, and IE50 were within ±0.09, ±0.03, and ±0.25, respectively. A comparison of resting breathing demonstrated that breath-by-breath and averaged agreements for all seven parameters were repeatable (P > 0.05). With increased RR, agreement improved for tI, tE, and tTot (P ≤ 0.01), did not differ for tI/tE, tI/tTot, and IE50 (P > 0.05) and reduced for breath-by-breath (P < 0.05) but not averaged RR (P > 0.05).

Tidal breathing patterns derived from structured light plethysmography in COPD patients compared with healthy subjects.

PURPOSE: Differences in tidal breathing patterns have been reported between patients with chronic obstructive pulmonary disease (COPD) and healthy individuals using traditional measurement techniques. This feasibility study examined whether structured light plethysmography (SLP) - a noncontact, light-based technique - could also detect differences in tidal breathing patterns between patients with COPD and healthy subjects. PATIENTS AND METHODS: A 5 min period of tidal (quiet) breathing was recorded in each patient with COPD (n=31) and each healthy subject (n=31), matched for age, body mass index, and sex. For every participant, the median and interquartile range (IQR; denoting within-subject variability) of 12 tidal breathing parameters were calculated. Individual data were then combined by cohort and summarized by its median and IQR. RESULTS: After correction for multiple comparisons, inspiratory time (median tI) and its variability (IQR of tI) were lower in patients with COPD (p<0.001 and p<0.01, respectively) as were ratios derived from tI (tI/tE and tI/tTot, both p<0.01) and their variability (p<0.01 and p<0.05, respectively). IE50SLP (the ratio of inspiratory to expiratory flow at 50% tidal volume calculated from the SLP signal) was higher (p<0.001) in COPD while SLP-derived time to reach peak tidal expiratory flow over expiratory time (median tPTEFSLP/tE) was shorter (p<0.01) and considerably less variable (p<0.001). Thoraco-abdominal asynchrony was increased (p<0.05) in COPD. CONCLUSION: These early observations suggest that, like traditional techniques, SLP is able to detect different breathing patterns in COPD patients compared with subjects with no respiratory disease. This provides support for further investigation into the potential uses of SLP in assessing clinical conditions and interventions.

Measuring changes in chest wall motion after lung resection using structured light plethysmography: a feasibility study.

OBJECTIVES: We describe the use of structured light plethysmography (SLP)-a novel, non-contact, light-based technique for measuring tidal breathing-among a cohort of patients undergoing lung resection. In this feasibility study, we examined whether changes in chest wall motion or in asynchrony between regions of the thoraco-abdominal wall could be identified after surgery. METHODS: Fifteen patients underwent wedge resection (n = 8) or lobectomy (n = 7). All patients underwent two SLP assessments (before surgery and on Day 1 post-surgery). Each assessment captured data during 5 min of quiet (tidal) breathing. RESULTS: When data were averaged across all patients, motion on the operated side of the thorax was significantly reduced after surgery (mean change from presurgery ± standard deviation: -14.7 ± 16.5%, P = 0.01), while motion on the non-operated side increased (15.9 ± 18.5%, P = 0.01). Thoraco-abdominal asynchrony also increased (mean change ± standard deviation: 43.4 ± 55.1%, P = 0.01), but no significant difference was observed in right-left hemi-thoracic asynchrony (163.7 ± 230.3%, P = 0.08). When analysed by resection type, lobectomy was associated with reduced and increased motion on the operated and non-operated side, respectively, and with an increase in both right-left hemi-thoracic and thoraco-abdominal asynchrony. No significant changes in motion or asynchrony were identified in patients who underwent wedge resection. CONCLUSIONS: SLP was able to detect changes in chest wall motion and asynchrony after thoracic surgery. Changes in this small group of patients were consistent with the side of the incision and were most apparent in patients undergoing lobectomy.

Stated Choice design comparison in a developing country: recall and attribute nonattendance.

BACKGROUND: Experimental designs constitute a vital component of all Stated Choice (aka discrete choice experiment) studies. However, there exists limited empirical evaluation of the statistical benefits of Stated Choice (SC) experimental designs that employ non-zero prior estimates in constructing non-orthogonal constrained designs. This paper statistically compares the performance of contrasting SC experimental designs. In so doing, the effect of respondent literacy on patterns of Attribute non-Attendance (ANA) across fractional factorial orthogonal and efficient designs is also evaluated. The study uses a 'real' SC design to model consumer choice of primary health care providers in rural north India. A total of 623 respondents were sampled across four villages in Uttar Pradesh, India. METHODS: Comparison of orthogonal and efficient SC experimental designs is based on several measures. Appropriate comparison of each design's respective efficiency measure is made using D-error results. Standardised Akaike Information Criteria are compared between designs and across recall periods. Comparisons control for stated and inferred ANA. Coefficient and standard error estimates are also compared. RESULTS: The added complexity of the efficient SC design, theorised elsewhere, is reflected in higher estimated amounts of ANA among illiterate respondents. However, controlling for ANA using stated and inferred methods consistently shows that the efficient design performs statistically better. Modelling SC data from the orthogonal and efficient design shows that model-fit of the efficient design outperform the orthogonal design when using a 14-day recall period. The performance of the orthogonal design, with respect to standardised AIC model-fit, is better when longer recall periods of 30-days, 6-months and 12-months are used. CONCLUSIONS: The effect of the efficient design's cognitive demand is apparent among literate and illiterate respondents, although, more pronounced among illiterate respondents. This study empirically confirms that relaxing the orthogonality constraint of SC experimental designs increases the information collected in choice tasks, subject to the accuracy of the non-zero priors in the design and the correct specification of a 'real' SC recall period.

Revenue effects of practice nurse-led care for chronic diseases.

OBJECTIVE: To determine the economic feasibility in Australian general practices of using a practice nurse (PN)-led care model of chronic disease management. METHODS: A cost-analysis of item numbers from the Medicare Benefit Schedule (MBS) was performed in three Australian general practices, one urban, one regional and one rural. Patients (n =254; >18 years of age) with chronic conditions (type 2 diabetes, hypertension, ischaemic heart disease) but without unstable or major health problems were randomised into usual general practitioner (GP) or PN-led care for management of their condition over a period of 12 months. After the 12-month intervention, total MBS item charges were evaluated for patients managed for their stable chronic condition by usual GP or PN-led care. Zero-skewness log transformation was applied to cost data and log-linear regression analysis was undertaken. RESULTS: There was an estimated A$129 mean increase in total MBS item charges over a 1-year period (controlled for age, self-reported quality of life and geographic location of practice) associated with PN-led care. The frequency of GP and PN visits varied markedly according to the chronic disease. CONCLUSIONS: Medicare reimbursements provided sufficient funding for general practices to employ PNs within limits of workloads before the new Practice Nurse Incentive Program was introduced in July 2012.

Thirty-years of screening for cystic fibrosis in East Anglia.

BACKGROUND: Newborn screening for cystic fibrosis (CF) relies on the measurement of immunoreactive trypsinogen (IRT) originating from the pancreas. The Norfolk, Suffolk and Cambridgeshire screening programme initially exploited the persistent increase in IRT seen in CF (IRT-IRT protocol) and later changed to include mutation analysis as a second tier test (IRT-DNA-IRT protocol). RESULTS: During a 30 year period 582 966 babies have been screened by IRT-IRT and 147 764 by IRT-DNA-IRT (total 730730), resulting in 296 screen positive cases of CF and 29 false negatives (including 10 false negatives with meconium ileus). Ten missed CF cases were pancreatic insufficient, however all were diagnosed before their first birthday, suggesting that a false negative result did not forestall appropriate clinical investigation. The IRT-DNA-IRT protocol had a much improved positive predictive value (PPV) of 85.9% compared to 67.3% for IRT-IRT, excluding CF babies with meconium ileus. The PPVs increased to 82.2% and 98.2% respectively if only well, term babies were considered. The main factor to account for this improvement in PPV has probably been the incorporation of DNA analysis in the second tier testing. CONCLUSIONS: The diagnosis of screen-positive babies proved difficult in a minority of cases with the classification of some patients changing with evolving phenotype. Our results illustrate the importance of collecting outcome data over a long time period for accurate assessment of the screening programme. This study provides evidence that newborn screening for CF is a valid undertaking that detects 95% of unsuspected CF cases presenting before 3 years of age.