Article Text


Compliance and reliability of electronic PEF monitoring in adolescents with asthma
  1. V van der Meer1,
  2. E R V M Rikkers-Mutsaerts2,
  3. P J Sterk3,
  4. H A Thiadens4,
  5. W J J Assendelft4,
  6. J K Sont5
  1. 1Departments of Medical Decision Making and Public Health and Primary Care, Leiden University Medical Center, Leiden, The Netherlands
  2. 2Department of Paediatrics, Leiden University Medical Center, Leiden, The Netherlands
  3. 3Department of Pulmonology, Leiden University Medical Center, Leiden, The Netherlands
  4. 4Department of Public Health and Primary Care, Leiden University Medical Center, Leiden, The Netherlands
  5. 5Department of Medical Decision Making, Leiden University Medical Center, Leiden, The Netherlands
  1. Correspondence to:
    MrV van der Meer
    Department of Medical Decision Making, J10-87, Leiden University Medical Center, P O Box 9600, NL-2300 RC Leiden, The Netherlands; V.van_der_Meer{at}

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Self-management education is the cornerstone of modern asthma care and consists of self-monitoring, transfer of information, a written action plan, and regular medical review.1 Current international guidelines recommend the use of home monitoring of peak expiratory flow (PEF) as a part of self-monitoring.2 PEF recordings potentially provide valuable information on risk prediction of asthma episodes and effectiveness of treatment.3 However, compliance and reliability of written PEF diaries is poor.4

Information and communication technologies (ICT) such as the internet and mobile phone short message service (SMS) are potentially powerful tools in the management of asthma. The use of these technologies enables adolescents to fit asthma management into their daily life activities. We therefore investigated the compliance and reliability of daily PEF measurements by adolescents with controlled and uncontrolled asthma symptoms using a handheld electronic spirometer and reporting the data via the internet or SMS.

Ninety seven adolescents aged 12–17 years with physician diagnosed asthma and regular prescriptions of low or medium dose inhaled corticosteroids for at least 3 months in the previous year were recruited from general practices and from the outpatient clinic of the department of paediatrics. Patients using systemic steroids, having no access to the internet, and those with serious co-morbidities were excluded. Participants and their parents gave written informed consent and the study was approved by the medical ethics committee of the Leiden University Medical Center, Leiden, the Netherlands.

All participants received an electronic spirometer (PiKo1; Ferraris, UK) and were trained to perform a forced expiratory manoeuvre. They were asked to perform three manoeuvres every morning before taking medication and to report PEF values by typing these daily on a designated web application or via SMS for 4 weeks. Participants instantly received a receipt message with the PEF value expressed as a percentage of their personal best value. They were unaware that the spirometer also stored the values in a memory chip. The participants completed the Asthma Control Questionnaire (ACQ) weekly.5

Reported compliance was defined as the proportion of reported PEF entries to the number of expected entries. Actual compliance was calculated as the proportion of entries in the spirometer memory to the number of expected entries. In order to evaluate reliability, the reported PEF values were compared with the spirometer memory: correctly reported values were identical to the spirometer memory values on the same day. We distinguished between controlled and uncontrolled asthma symptoms on the basis of the mean ACQ score over 4 weeks, a score of ⩽0.5 indicating controlled asthma and a score of >0.5 indicating uncontrolled asthma. Repeated measures analysis of variance was used to assess differences between the 4 weeks and between the two ACQ groups.

Mean (SD) PEF values were 419 (97) l/min and 378 (86) l/min for the controlled and uncontrolled groups, respectively (p = 0.052). Overall reported compliance was 90.6% and actual compliance was 91.5%. Actual compliance significantly decreased between week 1 (97.2%) and week 4 (83.7%; p<0.01, ANOVA). Correctly reported PEF values were found on 79.2% of the days; 2.2% of the PEF values were self-invented (table 1). There were no differences between ACQ groups.

Table 1

 Reliability of PEF values: mean (SD) percentages of correct, incorrect, self-invented, and missing values for patients with controlled and uncontrolled asthma symptoms

We conclude that the compliance and reliability of home PEF measurements by adolescents using the internet or SMS is high over a 4 week period. Actual compliance was over 83% during the whole period. Compared with conventional written diary cards, electronic monitoring and reporting seems to result in better compliance and reliability.4 The internet and SMS are both well established communication tools in the daily lives of adolescents, and this probably accounts for these remarkably good results. We observed a modest decline in compliance and an increase in erroneous reports over time which had not reached a plateau by week 4. The feasibility of long term ICT based monitoring by adolescents is therefore uncertain. In our observational study lung function monitoring was not followed by feedback and/or therapeutic consequences which might have negatively influenced compliance over time. Implementation of electronic monitoring into an asthma management programme in adults has shown continuing high compliance rates.6 This study supports the implementation and evaluation of electronic PEF monitoring as part of ICT based asthma management programmes in adolescents.


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  • Supported by a grant from the Netherlands Asthma Foundation.

  • Competing interests: none declared.

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