Predicting asthma in preschool children at high risk presenting in primary care: development of a clinical asthma prediction score.

BACKGROUND: A setting-specific asthma prediction score for preschool children with wheezing and/or dyspnoea presenting in primary healthcare is needed since existing indices are mainly based on general populations. AIMS: To find an optimally informative yet practical set of predictors for the prediction of asthma in preschool children at high risk who present in primary healthcare. METHODS: A total of 771 Dutch preschool children at high risk of asthma were followed prospectively until the age of six years. Data on asthma symptoms and environmental conditions were obtained using validated questionnaires and specific IgE was measured. At the age of six years the presence of asthma was assessed based on asthma symptoms, medication, and bronchial hyper-responsiveness. A clinical asthma prediction score (CAPS) was developed using bootstrapped multivariable regression methods. RESULTS: In all, 438 children (56.8%) completed the study; the asthma prevalence at six years was 42.7%. Five parameters optimally predicted asthma: age, family history of asthma or allergy, wheezing-induced sleep disturbances, wheezing in the absence of common colds, and specific IgE. CAPS scores range from 0 to 11 points; scores <3 signified a negative predictive value of 78.4% while scores of >7 signified a positive predictive value of 74.3%. CONCLUSIONS: We have developed an easy-to-use CAPS for preschool children with symptoms suggesting asthma who present in primary healthcare. After suitable validation, the CAPS may assist in guiding shared decision-making to tailor the need for medical or non-medical interventions. External validation of the CAPS is needed.

Morbidity and doctor characteristics only partly explain the substantial healthcare expenditures of frequent attenders: a record linkage study between patient data and reimbursements data.

BACKGROUND: Frequently attending patients to primary care (FA) are likely to cost more in primary care than their non-frequently attending counterparts. But how much is spent on specialist care of FAs? We describe the healthcare expenditures of frequently attending patients during 1, 2 or 3 years and test the hypothesis that additional costs can be explained by FAs' combined morbidity and primary care physicians' characteristics. METHODS: Record linkage study. Pseudonymised clinical data from the medical records of 16 531 patients from 39 general practices were linked to healthcare insurer's reimbursements data. Main outcome measures were all reimbursed primary and specialist healthcare costs between 2007 and 2009. Multilevel linear regression analysis was used to quantify the effects of the different durations of frequent attendance on three-year total healthcare expenditures in primary and specialist care, while adjusting for age, sex, morbidities and for primary care physicians characteristics. Primary care physicians' characteristics were collected through administrative data and a questionnaire. RESULTS: Unadjusted mean 3-year expenditures were 5044 and 15 824 Euros for non-FAs and three-year-FAs, respectively. After adjustment for all other included confounders, costs both in primary and specialist care remained substantially higher and increased with longer duration of frequent attendance. As compared to non-FAs, adjusted mean expenditures were 1723 and 5293 Euros higher for one-year and three-year FAs, respectively. CONCLUSIONS: FAs of primary care give rise to substantial costs not only in primary, but also in specialist care that cannot be explained by their multimorbidity. Primary care physicians' working styles appear not to explain these excess costs. The mechanisms behind this excess expenditure remain to be elucidated.

The effect of two lottery-style incentives on response rates to postal questionnaires in a prospective cohort study in preschool children at high risk of asthma: a randomized trial.

BACKGROUND: In research with long-term follow-up and repeated measurements, quick and complete response to questionnaires helps ensure a study's validity, precision and efficiency. Evidence on the effect of non-monetary incentives on response rates in observational longitudinal research is scarce. OBJECTIVES: To study the impact of two strategies to enhance completeness and efficiency in observational cohort studies with follow-up durations of around 2 years. METHOD AND INTERVENTION: In a factorial design, 771 children between 2 and 5 years old and their parents participating in a prospective cohort study were randomized to three intervention groups and a control group. Three types of lotteries were run: (i) daytrip tickets for the whole family to a popular amusement park if they returned all postal questionnaires, (ii) €12.50-worth gift vouchers for sending back the questionnaire on time after each questionnaire round and (iii) a combination of (i) and (ii). MAIN OUTCOME MEASURES: Primary outcome was the proportion of participants who returned all questionnaires without any reminder. Secondary outcomes were '100% returned with or without reminder', 'probability of 100% non-response', 'probability of withdrawal', 'proportion of returned questionnaires' and 'overall number of reminders sent'. STATISTICAL ANALYSIS: After testing for interaction between the two lottery interventions, the two trials were analysed separately. We calculated risk differences (RD) and numbers needed to "treat" and their 95% confidence intervals. RESULTS: Daytrip nor voucher intervention had an effect on the proportion of participants who returned all questionnaires (RD -0.01; 95% CI-0.07 - 0.06) and (RD 0.02; 95% CI-0.50 - 0.08), respectively. No effects were found on the secondary outcomes. CONCLUSION: Our findings do not support the idea that lottery-style incentives lead to more complete response to postal questionnaires in observational cohort studies with repeated data collection and follow-up durations of around 2 years.

A systematic review with attempted network meta-analysis of asthma therapy recommended for five to eighteen year olds in GINA steps three and four.

BACKGROUND: The recommendations for the treatment of moderate persistent asthma in the Global Initiative for Asthma (GINA) guidelines for paediatric asthma are mainly based on scientific evidence extrapolated from studies in adults or on consensus. Furthermore, clinical decision-making would benefit from formal ranking of treatments in terms of effectiveness.Our objective is to assess all randomized trial-based evidence specifically pertaining to 5-18 year olds with moderate persistent asthma. Rank the different drug treatments of GINA guideline steps 3&4 in terms of effectiveness. METHODS: Systematic review with network meta-analysis. After a comprehensive search in Central, Medline, Embase, CINAHL and the WHO search portal two reviewers selected RCTs performed in 4,129 children from 5-18 year old, with moderate persistent asthma comparing any GINA step 3&4 medication options. Further quality was assessed according the Cochrane Collaboration's tool and data-extracted included papers and built a network of the trials. Attempt at ranking treatments with formal statistical methods employing direct and indirect (e.g. through placebo) connections between all treatments. RESULTS: 8,175 references were screened; 23 randomized trials (RCT), comparing head-to-head (n=17) or against placebo (n=10), met the inclusion criteria. Except for theophylline as add-on therapy in step 4, a closed network allowed all comparisons to be made, either directly or indirectly. Huge variation in, and incomplete reporting of, outcome measurements across RCTs precluded assessment of relative efficacies. CONCLUSION: Evidence-based ranking of effectiveness of drug treatments in GINA steps 3&4 is not possible yet. Existing initiatives for harmonization of outcome measurements in asthma trials need urgent implementation.

Prediction and treatment of asthma in preschool children at risk: study design and baseline data of a prospective cohort study in general practice (ARCADE).

BACKGROUND: Asthma is a difficult diagnosis to establish in preschool children. A few years ago, our group presented a prediction rule for young children at risk for asthma in general practice. Before this prediction rule can safely be used in practice, cross-validation is required. In addition, general practitioners face many therapeutic management decisions in children at risk for asthma. The objectives of the study are: (1) identification of predictors for asthma in preschool children at risk for asthma with the aim of cross-validating an earlier derived prediction rule; (2) compare the effects of different treatment strategies in preschool children. DESIGN: In this prospective cohort study one to five year old children at risk of developing asthma were selected from general practices. At risk was defined as 'visited the general practitioner with recurrent coughing (>or= 2 visits), wheezing (>or=1) or shortness of breath (>or=1) in the previous 12 months'. All children in this prospective cohort study will be followed until the age of six. For our prediction rule, demographic data, data with respect to clinical history and additional tests (specific immunoglobulin E (IgE), fractional exhaled nitric oxide (FENO), peak expiratory flow (PEF)) are collected. History of airway specific medication use, symptom severity and health-related quality of life (QoL) are collected to estimate the effect of different treatment intensities (as expressed in GINA levels) using recently developed statistical techniques. In total, 1,938 children at risk of asthma were selected from general practice and 771 children (40%) were enrolled. At the time of writing, follow-up for all 5-year olds and the majority of the 4-year olds is complete. The total and specific IgE measurements at baseline were carried out by 87% of the children. Response rates to the repeated questionnaires varied from 93% at baseline to 73% after 18 months follow-up; 89% and 87% performed PEF and FENO measurements, respectively. DISCUSSION: In this study a prediction rule for asthma in young children, to be used in (general) practice, will be cross-validated. Our study will also provide more insight in the effect of treatment of asthma in preschool children.

Defining frequent attendance in general practice.

BACKGROUND: General practitioners (GPs) or researchers sometimes need to identify frequent attenders (FAs) in order to screen them for unidentified problems and to test specific interventions. We wanted to assess different methods for selecting FAs to identify the most feasible and effective one for use in a general (group) practice. METHODS: In the second Dutch National Survey of General Practice, data were collected on 375 899 persons registered with 104 practices. Frequent attendance is defined as the top 3% and 10% of enlisted patients in each one-year age-sex group measured during the study year. We used these two selections as our reference standard. We also selected the top 3% and 10% FAs (90 and 97 percentile) based on four selection methods of diminishing preciseness. We compared the test characteristics of these four methods. RESULTS: Of all enlisted patients, 24 % did not consult the practice during the study year. The mean number of contacts in the top 10% FAs increased in men from 5.8 (age 15-24 years) to 17.5 (age 64-75 years) and in women from 9.7 to 19.8. In the top 3% of FAs, contacts increased in men from 9.2 to 24.5 and in women from 14 to 27.8. The selection of FAs becomes more precise when smaller age classes are used. All selection methods show acceptable results (kappa 0.849 - 0.942) except the three group method. CONCLUSION: To correctly identify frequent attenders in general practice, we recommend dividing patients into at least three age groups per sex.

Why do they keep coming back? Psychosocial etiology of persistence of frequent attendance in primary care: a prospective cohort study.

BACKGROUND: Patients who visit their General Practitioner (GP) very frequently over extended periods of time often have multimorbidity and are costly in primary and specialist healthcare. We investigated the impact of patient-level psychosocial and GP-level factors on the persistence of frequent attendance (FA) in primary care. METHODS: Two-year prospective cohort study in 623 incident adult frequent attenders (>90th attendance centile; age and sex-adjusted) in 2009. Information was collected through questionnaires (patients, GPs) and GPs' patient data. We used multilevel, ordinal logistic regression analysis, controlling for somatic illness and demographic factors with FA in 2010 and/or 2011 as the outcome. RESULTS: Other anxiety (odds ratio (OR) 2.00; 95% confidence interval from 1.29 to 3.10) over 3years and the number of life events in 3years (OR 1.06; 1.01-1.10 per event; range of 0 to 12) and, at baseline, panic disorder (OR 5.40; 1.67-17.48), other anxiety (OR 2.78; 1.04-7.46), illness behavior (OR 1.13; 1.05-1.20 per point; 28-point scale) and lack of mastery (OR 1.08; 1.01-1.15 per point; 28-point scale) were associated with persistence of FA. We found no evidence of synergistic effects of somatic, psychological and social problems. We found no strong evidence of effects of GP characteristics. CONCLUSION: Panic disorder, other anxiety, negative life events, illness behavior and lack of mastery are independently associated with persistence of frequent attendance. Effective intervention at these factors, apart from their intrinsic benefits to these patients, may reduce attendance rates, and healthcare expenditures in primary and specialist care.

Culturally adapted hypertension education (CAHE) to improve blood pressure control and treatment adherence in patients of African origin with uncontrolled hypertension: cluster-randomized trial.

OBJECTIVES: To evaluate the effect of a practice-based, culturally appropriate patient education intervention on blood pressure (BP) and treatment adherence among patients of African origin with uncontrolled hypertension. METHODS: Cluster randomised trial involving four Dutch primary care centres and 146 patients (intervention n=75, control n=71), who met the following inclusion criteria: self-identified Surinamese or Ghanaian; ≥ 20 years; treated for hypertension; SBP ≥ 140 mmHg. All patients received usual hypertension care. The intervention-group was also offered three nurse-led, culturally appropriate hypertension education sessions. BP was assessed with Omron 705-IT and treatment adherence with lifestyle- and medication adherence scales. RESULTS: 139 patients (95%) completed the study (intervention n=71, control n=68). Baseline characteristics were largely similar for both groups. At six months, we observed a SBP reduction of ≥ 10 mmHg -primary outcome- in 48% of the intervention group and 43% of the control group. When adjusted for pre-specified covariates age, sex, hypertension duration, education, baseline measurement and clustering effect, the between-group difference was not significant (OR; 0.42; 95% CI: 0.11 to 1.54; P=0.19). At six months, the mean SBP/DBD had dropped by 10/5.7 (SD 14.3/9.2)mmHg in the intervention group and by 6.3/1.7 (SD 13.4/8.6)mmHg in the control group. After adjustment, between-group differences in SBP and DBP reduction were -1.69 mmHg (95% CI: -6.01 to 2.62, P=0.44) and -3.01 mmHg (-5.73 to -0.30, P=0.03) in favour of the intervention group. Mean scores for adherence to lifestyle recommendations increased in the intervention group, but decreased in the control group. Mean medication adherence scores improved slightly in both groups. After adjustment, the between-group difference for adherence to lifestyle recommendations was 0.34 (0.12 to 0.55; P=0.003). For medication adherence it was -0.09 (-0.65 to 0.46; P=0.74). CONCLUSION: This intervention led to significant improvements in DBP and adherence to lifestyle recommendations, supporting the need for culturally appropriate hypertension care. TRIAL REGISTRATION: Controlled-Trials.com ISRCTN35675524.

Predictability of persistent frequent attendance in primary care: a temporal and geographical validation study.

BACKGROUND: Frequent attenders are patients who visit their general practitioner exceptionally frequently. Frequent attendance is usually transitory, but some frequent attenders become persistent. Clinically, prediction of persistent frequent attendance is useful to target treatment at underlying diseases or problems. Scientifically it is useful for the selection of high-risk populations for trials. We previously developed a model to predict which frequent attenders become persistent. AIM: To validate an existing prediction model for persistent frequent attendance that uses information solely from General Practitioners' electronic medical records. METHODS: We applied the existing model (N = 3,045, 2003-2005) to a later time frame (2009-2011) in the original derivation network (N = 4,032, temporal validation) and to patients of another network (SMILE; 2007-2009, N = 5,462, temporal and geographical validation). Model improvement was studied by adding three new predictors (presence of medically unexplained problems, prescriptions of psychoactive drugs and antibiotics). Finally, we derived a model on the three data sets combined (N = 12,539). We expressed discrimination using histograms of the predicted values and the concordance-statistic (c-statistic) and calibration using the calibration slope (1 = ideal) and Hosmer-Lemeshow tests. RESULTS: The existing model (c-statistic 0.67) discriminated moderately with predicted values between 7.5 and 50 percent and c-statistics of 0.62 and 0.63, for validation in the original network and SMILE network, respectively. Calibration (0.99 originally) was better in SMILE than in the original network (slopes 0.84 and 0.65, respectively). Adding information on the three new predictors did not importantly improve the model (c-statistics 0.64 and 0.63, respectively). Performance of the model based on the combined data was similar (c-statistic 0.65). CONCLUSION: This external validation study showed that persistent frequent attenders can be prospectively identified moderately well using data solely from patients' electronic medical records.

Opening the black box: the patient mix of GP trainees.

BACKGROUND: The variety of health problems (patient mix) that medical trainees encounter is presumed to be sufficient to master the required competencies. AIM: To describe the patient mix of GP trainees, to study differences in patient mix between first-year and third-year GP trainees, and to investigate differences in exposure to sex-specific diseases between male and female trainees. DESIGN AND SETTING: Prospective cohort study in Dutch primary care. METHOD: During a 6-month period, aggregated data about International Classification of Primary Care diagnosis codes, and data on the sex and age of all contacts were collected from the electronic patient record (EPR) system. RESULTS: Seventy-three trainees participated in this study. The mean coding percentage was 86% and the mean number of face-to-face consultations per trimester was 450.0 in the first year and 485.4 in the third year, indicating greater variance in the number of patient contacts among third-year trainees. Diseases seen most frequently were: musculoskeletal (mean per trimester = 89.2 in the first year/91.0 in the third year), respiratory (98.2/92.7) and skin diseases (89.5/96.0). Least often seen were diseases of the blood and blood-forming organs (5.3/7.2), male genital disorders (6.1/7.1), and social problems (4.3/4.2). The mean number of chronic diseases seen per trimester was 48.0 for first-year trainees and 62.4 for third-year trainees. Female trainees saw an average of 39.8 female conditions per trimester--twice as many as male trainees (mean = 21.3). CONCLUSION: Considerable variation exists trainees in the number of patient contacts. Differences in patient mix between first- and third-year trainees seem at least partly related to year-specific learning objectives. The use of an EPR-derived educational instrument provides insight into the trainees' patient mix at both the group and the individual level. This offers opportunities for GP trainers, trainees, and curriculum designers to optimise learning when exposure may be low.

Pilot study evaluating the effects of an intervention to enhance culturally appropriate hypertension education among healthcare providers in a primary care setting.

BACKGROUND: To improve hypertension care for ethnic minority patients of African descent in the Netherlands, we developed a provider intervention to facilitate the delivery of culturally appropriate hypertension education. This pilot study evaluates how the intervention affected the attitudes and perceived competence of hypertension care providers with regard to culturally appropriate care. METHODS: Pre- and post-intervention questionnaires were used to measure the attitudes, experienced barriers, and self-reported behaviour of healthcare providers with regard to culturally appropriate cardiovascular and general care at three intervention sites (N = 47) and three control sites (N = 35). RESULTS: Forty-nine participants (60%) completed questionnaires at baseline (T0) and nine months later (T1). At T1, healthcare providers who received the intervention found it more important to consider the patient's culture when delivering care than healthcare providers who did not receive the intervention (p = 0.030). The intervention did not influence experienced barriers and self-reported behaviour with regard to culturally appropriate care delivery. CONCLUSION: There is preliminary evidence that the intervention can increase the acceptance of a culturally appropriate approach to hypertension care among hypertension educators in routine primary care.

Two simple strategies (adding a logo or a senior faculty's signature) failed to improve patient participation rates in a cohort study: randomized trial.

BACKGROUND: Patient participation in research studies is often difficult to achieve, and efforts to increase participation rates fail frequently. Given the paucity of evidence on interventions aimed at improving patient participation, we conducted a randomized trial. OBJECTIVES: The first was to assess the effect of the logo of the funding agency on the willingness to consider participation in a prospective cohort study in general practice. The second objective was to assess the effect of two signatures of senior persons on the participation rate in the study. STUDY DESIGN AND SETTING: Parents of 1-5-year-old children at a 'high risk' of developing asthma received general information with or without the logo of the Netherlands Asthma Foundation (=RCT1). In addition, the detailed information was signed by the director of the Netherlands Asthma Foundation and the professor of the department vs. the junior researcher (=RCT2). RESULTS: One thousand nine hundred and thirty-eight children were randomized (RCT1). In the 'logo arm,' 46.4% parents considered participation compared to 48.8% parents in the control arm, the difference being -2.3 (95% CI from -6.0 to 1.4). Eight hundred and sixty-two children were randomized in RCT2. Fifty percent of the parents in the 'senior signature arm' and 54.4% in the 'junior signature arm' decided to participate (difference -4.4, 95% CI from -12.1 to 3.3). The overall participation rate, after additional telephone calls, was 37%. CONCLUSION: Our findings indicate that emphasizing the support of a funding agency and senior persons does not improve participation rates in a prospective cohort study.