Optimising Diagnosis and Antibiotic Prescribing for Acutely Ill Children in Primary Care
Optimising Diagnosis and Antibiotic Prescribing for Acutely Ill Children in Primary Care
Acute illness is the most common presentation of children attending ambulatory care settings.
 Serious infections (e.g. meningitis, sepsis, pyelonephritis, pneumonia) are rare, but their
 impact is quite large (increased morbidity, mortality, induced fear in parents and defensive
 behaviour in clinicians). Early recognition and adequate referral of serious infections are
 essential to avoid complications (e.g. hearing loss after bacterial meningitis) and their
 accompanied mortality. Secondly, we aim to reduce the number of investigations, referrals,
 treatments and hospitalisations in children who are diagnosed with a non-serious infection.
 Apart from the cost-effectiveness, this could lead to less traumatic experiences for the
 child and less fear induction for the concerned parent. Finally, we aim to support the
 clinicians to rationalise their antibiotic prescribing behaviour, resulting in a reduction of
 antibiotic resistance in the long run.
This study is a combination of a diagnostic and an intervention study. In a previous study,
 our research team constructed a decision tree, based on signs and symptoms, to identify
 serious infections in acutely ill children in primary care. This decision tree had an
 excellent sensitivity of 97% for the detection of serious infections, but would have lead to
 12% of all acutely ill children to be referred, which is unacceptably high.

 Our main research questions are:

 1. In addition to measuring clinical signs and symptoms, can new or existing technology
 help identify serious infections in acutely ill children in ambulatory care? Translated
 to our study design: "After applying the decision tree, can we further reduce the number
 of false positives (and thus increase the specificity) and maintain the same level of
 sensitivity with a C-reactive Protein Point-of-Care test or pulse oximetry?

 2. After excluding children with serious illnesses by applying the decision tree, can a
 Point-of-Care CRP test, a brief intervention together with a parent leaflet, or both,
 have effect on:

 A. Primary outcome measure:

 1. Serious infection

 2. Immediate antibiotic prescribing rates

 B. Secondary outcome measures:

 3. Parental satisfaction

 4. Parental concern

 5. Use of other diagnostic tests and medical services (including re-consultation)

 6. Cost-effectiveness

 7. Impact of the communicator style on the effect of the intervention (interaction)

 Serious infections will be defined as:

 A hospital admission for more than 24 hours for any of these diagnoses:

 1. Sepsis (including bacteraemia) with a pathogenic bacteria isolated from a haemoculture
 as the reference standard

 2. Meningitis (viral or bacterial) with a positive lumbar puncture (pleocytosis in
 cerebrospinal fluid and identification of a bacteria or a virus) as the reference
 standard

 3. Abscess (with a positive culture)

 4. Pneumonia (viral or bacterial) with an infiltrate seen on chest x-ray as the reference
 standard

 5. Osteomyelitis (pathogens from bone aspirate as the reference standard, or if unavailable
 with a MRI or bone scan suggestive for osteomyelitis)

 6. Cellulitis (acute suppurative inflammation of the subcutaneous tissues)

 7. Gastro-enteritis with dehydration

 8. Complicated urinary tract infection (positive urine culture (>105/ml pathogens of a
 single species) and systemic effects such as fever)

 9. Viral respiratory tract infections complicated by hypoxia (e.g. bronchiolitis)

 This is a combination of (I) a diagnostic study in ambulatory care (consisting of general
 practitioners and ambulatory paediatricians) identifying the diagnostic value of signs,
 symptoms and technological tests using hospital admission more than 24 hours for a serious
 infection as the main outcome and (II) an open, randomised, controlled trial with
 randomisation at practice level.

 Clinicians will be allocated to 1 of these 4 intervention groups (table 1):

 These interventions will be performed on children testing negative on the decision tree:

 1. Use of C-reactive protein (CRP) point of care test and brief intervention and parent
 leaflet

 2. Use of C-reactive protein point of care test

 3. Brief intervention and parent leaflet

 4. Usual care

 All clinicians will be trained to properly perform the point-of-care CRP test. When a child
 tests positive on the 5-stage decision tree, a point-of-care CRP test will be performed in
 all 4 intervention groups. Only clinicians in group 1 and 3 will be trained in the brief
 intervention and handling of the parent information leaflet. All clinicians will be asked to
 measure oxygen saturation by means of a paediatric finger pulse oximeter, which will be
 provided to all physicians.

 2.1 Randomisation To avoid contamination, a clustered randomised study design was chosen.
 Each cluster is made up of one practice. A minimum condition to participate as a practice is
 being able to recruit 36 children during 1 year. A first randomisation procedure will create
 2 groups: CRP point of care test or no testing. A second randomisation procedure will create
 2 more groups: brief intervention and parent information leaflet or no
 communication-intervention.

 To ensure a good balance of the different practice structures (solo versus
 duo/group/community health centre) and practice types (general versus paediatric practices)
 between the recruitment arms, the randomisation process will be stratified.

 2.2 Sample size calculation A. Diagnostic part Based on the binomial distribution, at an
 expected sensitivity of 97% with a minimal acceptable lower confidence limit of 85%, the
 minimal number of cases is 59, not taking into account the non-monotonic nature of power as a
 function of sample size due to discreteness of the binomial distribution.[17] The number of
 controls, derived through the formula Ncontrols =Ncases [(1-Prev)/Prev],[18] is 7316 at a
 prevalence of 0.8% and 6497 at a prevalence of 0.9%.

 A recent developed nomogram to calculate sample size in diagnostic studies was not useful,
 because prevalences below 0.01 were not computed in the nomogram.[19]

 B. Therapeutic part In order to detect an absolute reduction in antibiotic prescribing of 15%
 (from 40% to 25%), with 80% power at a 5% significance level, an individually randomised
 study will need 656 patients (164 patients per group, 4 groups).

 If we randomise 72 practices with an intracluster correlation coefficient (icc) of 0.06, this
 number increases to a total of 1368 patients (19 patients per cluster).

 In order to allow for a 90% follow-up rate for the primary outcome measure of antibiotic
 prescribing, and at least 70% well recruiting practices, we need to recruit 2184 patients
 (104 practices, 21 per practice and 546 patients in each cell).

 2.3 Practices We intend to recruit 92 general practices and 12 paediatric practices. In every
 group practice, at least 2 practitioners will be recruiting. The recruited practices will be
 situated throughout Flanders, in urban and rural areas. Physicians will be excluded if the
 assumption of consecutive inclusion was violated (inclusion of less than two children in 1
 month time). Physicians will be asked to complete a survey on communication skills to
 stratify the intervention groups, according to communicator style. After formal approval,
 physicians will be asked to provide us with their latest report on antibiotic prescribing
 profile, as provided by the Belgian National Health and Disability Insurance (RIZIV).

 2.4 Patients Patients aged 1 month to 16 years with an acute illness for a maximum of 5 days
 are included consecutively. Children are excluded if the acute episode was caused by a merely
 traumatic or neurological illness, intoxication, psychiatric or behavioural problem without
 somatic cause, or an exacerbation of a known chronic condition. If a physician includes
 children twice in the study within 5 days, the second registration is considered a repeated
 measurement on the same subject and is subsequently excluded from the analysis.

 2.5 CRP point of care test A pilot study was performed to determine the user-friendliness,
 technical accuracy, inter-device and inter-observer variability of the selected point-of-care
 CRP devices.

 Based on a recent horizon scanning report by the Monitoring and Diagnosis Group in Oxford
 (Department of Primary Health Care) and thorough review of the existing technologies in
 point-of-care CRP devices through industry contacts, we assembled an up-to-date list of all
 available devices.

 For use in children the sample size had to be less than 5 µl and the test duration less than
 5 minutes.

 Two point-of-care CRP devices (Afinion™ AS100 Analyzer by Axis-Shield and the LifeAssays™
 Reader by LifeAssays) met our criteria and were included in the pilot study.

 We evaluated both devices based on these criteria: device start-up, test duration, sample
 size, test characteristics, calibration, measuring range, handling of test tubes, filling of
 the capillary, placing the test cartridge, test recording and additional material usage.

 CRP values were measured on two different point-of-care CRP devices in 100 children and
 compared with the laboratory CRP results in hospitalised children and children consulting an
 outpatient paediatric clinic of a university hospital. To verify whether the devices were
 user-friendly and reliable, a CRP measurement was performed on children and adults attending
 in 5 General Practice surgeries by 2 different Point-of-Care CRP devices. The inter-device
 (by 1 physician) and inter-observer (by two physicians) variability was tested on 10 patients
 in one GP surgery each on two different POC devices of the same brand.

 During the pilot study, one device failed to meet these standards of user-friendliness and
 test accuracy and was deemed unsuitable for further use in our study. (LifeAssays™ Reader) A
 perfect correlation was found between the results from the other point-of-care CRP device
 (Afinion™ Analyzer) and the laboratory results. No significant inter-observer and
 inter-device variability was found. The device was well received by the users and scored high
 on user-friendliness.

 All clinicians will have a CRP test device (Afinion™, Axis-Shield) at their disposal.

 CRP analysis will be performed during the consultation in accordance with the manufacturer's
 instructions. The Afinion™ CRP Test Cartridge consist of a 1.5 µL glass capillary to be
 filled with blood from a finger prick and a reagent container. First, the sample is
 automatically diluted with a liquid that also lyses the blood cells. If the sample is whole
 blood, the haematocrit value is estimated from transmission measurement of the haemoglobin.
 In this case, the measured CRP value will be automatically corrected according to the
 sample's haematocrit (Hct) level, and the result is displayed as the serum-CRP concentration.

 Then, the sample mixture is aspirated through the membrane coated with anti-CRP antibodies,
 and all CRP in the sample is concentrated onto this membrane. The conjugate solution
 containing anti-CRP antibodies labelled with ultra-small gold particles is then sucked
 through the membrane. The gold-antibody conjugate binds to the immobilized CRP on the
 membrane, which will turn red-brown. Excess gold-antibody conjugate is removed by a washing
 solution. The analyser measures the colour intensity of the membrane, which is proportional
 to the amount of CRP in the sample. The CRP concentration is displayed on the screen. The
 result is available within 4 minutes.

 The CRP measuring range is 8-200 mg/L. The results are displayed in intervals of 1 mg/L. If
 the CRP concentration in a whole blood sample exceeds the range 8-200 mg/L, CRP >200 mg/L
 will be displayed on the screen. The haematocrit measuring range is 20-60%. If the Hct value
 is outside this range, an information code will be displayed on the screen. For internal
 quality a control positive will be measured to confirm the efficacy and correct performance
 of the test in the beginning and the middle of the study period. The CRP point of care test
 will be performed in case of a positive decision tree (irrespective of the intervention
 group) and also in case of a negative decision tree by clinicians of intervention group 1 and
 2. Because no reliable cut-off points for CRP are known currently (as this is the aim of this
 study) for acute infections in children in primary care (nor for referral, nor for
 prescription of antibiotics), clinicians will not be given guidance on the interpretation of
 the CRP results.

 We will not impose restrictions on the clinicians about treatment, other technical
 investigations nor referrals.

 The device distributor will provide technical assistance. All clinicians will be trained in
 the use of the CRP device prior to the start of the study.

 2.6 Finger Pulse Oximeter All physicians will be asked to perform a measurement of the oxygen
 saturation on all children and enter the results on the case report form. The selected device
 is a clip-on system suitable for use in children, which measures oxygen saturation in the
 capillary blood as well as the pulse rate.

 2.7 Brief intervention and parent information leaflet

 Brief interventions are commonly used to give opportunistic advice, discussion, negotiation
 or encouragement. Mostly they take between 5 to 10 minutes. The effect of brief interventions
 is studied most extensively in the area of smoking cessation, alcohol misuse and increasing
 physical activity.

 We will use the brief intervention technique to serve another purpose, namely not to change
 the patient's, but rather the clinician's behaviour.

 Our goal is to reduce the numbers of antibiotic prescriptions. As described before, parents
 have a lot of concerns about the illness of their child and mostly they do not succeed in
 communicating these concerns clearly to their physician. Our hypothesis is that clinicians
 sometimes feel as, although they try to reassure the parents that the child will get better
 with symptomatic treatment, they do not convince them enough and prescribe antibiotics to
 reach adequate reassurance whenever the slightest doubt exists that the child benefits from
 the medication. To meet this gap, we developed a brief intervention: we'll ask the clinicians
 to ask 3 specific questions, namely "Are you concerned?", "What exactly concerns you?" and
 "Why does this concern you?". This intervention is easy to implement in daily practice and no
 additional training is required.

 Secondly, we aim to reduce the improper demand for antibiotics by the parents. As described
 before, parents contact their clinician when they feel they are losing control over the
 illness, e.g. when the child is having very high fever they cannot get down, or the child
 doesn't stop crying, or doesn't want to eat or sleep anymore. Mostly they already tried some
 methods to reduce fever or other symptoms, but failed in taking control over the situation.
 They still believe that antibiotics are the strongest medication you can get and hope to get
 them from the clinician when they visit him. We developed a parent information leaflet that
 gives information about what they can do when their child is ill, which signs are important
 to follow up and when they really should get advice from a clinician. This could make it
 easier for them to cope with an ill child. The clinician could use this leaflet to give
 advice and make clear when they have to re-consult their physician to re-evaluate the child.
 Our hypothesis is that through creating this safety net, the improper demand for antibiotics
 could be reduced.

 2.8 Data collection Acutely ill children (0 to 16 years old) presenting in ambulatory care
 (general practitioner or paediatrician) will be asked to participate in this trial.

 Eligible children (if applicable) and their parents will receive an information leaflet. The
 clinician will ask them to sign the informed consent form. Every participating child is
 allocated to an individual research number. Only the number, and not the name of the child,
 will be mentioned on the registration forms to ensure anonymity. Only the clinician and
 research assistant will know which child correlates to which number. This is needed to ensure
 the follow up of the child. The name of the child will not be mentioned in a database or
 scientific publication.

 During history taking, clinicians participating in group 1 and group 3 will ask the brief
 intervention questions. After a thorough clinical examination, including measurement of the
 oxygen saturation, the clinician runs the decision tree. If the child scores positive, he
 will execute a POC-CRP-test. If the child scores negative, the intervention will depend on
 the intervention arm: clinicians participating in group 1 and 2 will execute a POC-CRP-test
 anyway, clinicians participating in group 1 and 3 will hand over the parent information
 leaflet and clinicians participating in group 4 will pursue usual care.

 The clinician records the gathered data, working diagnosis and planned actions (e.g.
 investigations, treatment) on a registration form. After the consultation, parents complete a
 survey about parental concern and satisfaction about the consultation process and the
 clinician's communication, which will be posted in a sealed box at the clinician's office.
 This survey includes the 26 questions of the "Parental Medical Interview Satisfaction
 Scale"(7 points Likert scale)[20], 4 questions about communication of the "Parent's
 perceptions of Primary Care items" (5 points Likert scale).[21] Both instruments were
 translated into Dutch, which was ensured through a forward-back-translation process. After
 translation, they were validated again in a pilot study. The parental concern survey was
 developed by our research team and consists of 2 Visual Analog Scales about concern before
 and after the consultation and a short questionnaire about the content of the concern. This
 survey was also validated in a pilot study.

 At the end of the consultation, parents will get a follow up diary, which should be filled in
 daily, namely a 4 item scale about degree of illness (evaluated by the parent) and parental
 concern, fever and eating, drinking, crying, playing and sleeping behaviour. Additionally, we
 will ask the parents to complete questions about educational level, social background and
 whether they consulted another physician during the same illness episode.

 If parents score all items of the scale as "no problem", the child is considered as "cured".
 At that time, we'll ask the parents to send us a short text message. Parents who do so, will
 participate in a monthly lottery (motivational gift). Parents will be able to forward the
 diary to the clinical research associate or bring them to their GP in a prepaid envelope.

 Participating clinicians will complete a questionnaire about their defensive attitude once
 during the study period.

 2.9 Patient follow up

 Our research team will register the children as "cured" after receiving the short text
 message or the diary. If needed, reminders to complete the study documents will be sent by
 post after 14 days. If there is no response, the research team will contact the parents by
 telephone (at least 3 attempts). In the last case, the clinician, who initially recorded the
 case, will be contacted to verify if the child completely healed or was referred to the
 hospital. In case of referral and/or hospitalisation, the primary care and hospital
 clinicians will be contacted to reconstruct the illness episode (reason for
 referral/hospitalisation, diagnosis, time to cure).

 3.0 Analysis

 Primary outcome measure:

 1. Immediate antibiotic prescribing rates This will be registered by the clinician on the
 CRF and a Chi square or Fisher's exact test will determine the significance of the
 difference in results between the intervention groups. The results will be adjusted for
 relevant patient- or clinician-based characteristics using multiple logistic regression.

 2. Diagnostic Accuracy of 5-stage decision tree and added value of technology
 (point-of-care CRP testing and oxygen saturation) The diagnostic accuracy of the 5-stage
 decision tree will be tested and reported in sensitivity, specificity, positive and
 negative likelihood ratios, and positive and negative predictive values. Whenever
 possible, Receiver Operation Characteristic (ROC) curves will be plotted.

 The value of the point-of-care CRP test and the oxygen saturation will each be added to
 the 5-stage decision tree and compared to the results of the 5-stage decision tree
 alone, to determine the added value of the added technology in terms of sensitivity,
 specificity, positive and negative likelihood ratios, and positive and negative
 predictive values.

 Secondary outcome measures:

 3. Parental satisfaction This will be registered by the parents through a questionnaire
 (see above). The results will be compared between the intervention groups, evaluating
 their significance through a Chi square or Fisher's exact test.

 4. Parental concern This will be registered by the parents through a parental concern
 satisfaction survey (see above). The results will be compared between the intervention
 groups, evaluating their significance through a Chi square or Fisher's exact test.

 5. Use of other diagnostic tests and medical services (including re-consultation) This will
 be registered by the clinician on the CRF and checked by the research team. (including
 the number of re-consultations) The time to complete cure will be evaluated through
 registration by the parents in the fever diary and checked by the research team. The
 results will be compared between the intervention groups, evaluating their significance
 through a Chi square or Fisher's exact test.

 6. Cost-effectiveness A preliminary cost-effectiveness study will be performed evaluating
 the costs related to use of diagnostic tests and medical services and hospital costs
 compared to the cost of applying the requested interventions and the possible effect on
 antibiotic prescribing rates.

 7. Influence of the communicator style on the effect of the intervention (interaction) This
 will be registered by the clinician on a communication survey. The results will be
 stratified according to the communicator styles and compared between the intervention
 groups, evaluating their significance through a Chi square or Fisher's exact test.
Inclusion Criteria:

 -  Patients aged 1 month to 16 years with an acute illness for a maximum of 5 days are
 included consecutively.

 Exclusion Criteria:

 -  Children are excluded if the acute episode was caused by a merely traumatic or
 neurological illness, intoxication, psychiatric or behavioural problem without somatic
 cause, or an exacerbation of a known chronic condition. If a physician includes
 children twice in the study within 5 days, the second registration is considered a
 repeated measurement on the same subject and is subsequently excluded from the
 analysis.