Biomedical subjects

Timothy L Frank

Publications and source records attributed to Timothy L Frank.

6 recordsLinked to original sources

PubMed2006

The diagnostic accuracies of chronic obstructive pulmonary disease (COPD) in general practice: The results of the MAGIC (Manchester Airways Group Identifying COPD) study.

BACKGROUND: Although it is generally accepted that chronic obstructive pulmonary disease (COPD) is underdiagnosed, there is little objective information concerning the size of the problem in the UK. METHOD: Patients from two general practices were offered spirometry if they were aged 30 or older, had reported ever smoking in one of four postal respiratory surveys (1993-2001), and/or reported four or more symptoms or risk factors in 2001 indicating likely obstructive airways disease. RESULTS: Of 2646 subjects invited, 871 attended and 825 had adequate spirometry results for analysis. In all, 163 patients had spirometrically-confirmed COPD; 103 of these (63.2%) had no recorded COPD in their practice records, including 14 out of 31 (45.2%) whose spirometry results classified them as having severe or very severe COPD. CONCLUSION: This study found a considerable under-recording of COPD in two general practices. This may be due to a combination of administrative and diagnostic problems (including the under-use of spirometers), and a reluctance of patients to present with their symptoms. These results have important implications in terms of unmet need and resource utilisation.

Adult↗

PubMed2005

Screening for asthma by population ranking: a validation study.

PURPOSE: A neural network system was previously developed to rank a population in order of asthma probability based on responses to a postal questionnaire. Respondents ranked higher than a percentage point screening threshold are offered clinical review. The present study validates this system in a new population that had not been involved in system development. METHODS: The system was used to rank respondents to a community survey and to predict positive predictive value (PPV) for percentage point thresholds between the top 1% and 10% of the ranking. Respondents in the top 10% were invited for clinical review. Review information and expert opinion was used to designate respondents as clinically "asthmatic" or "non-asthmatic." PPV prediction for each threshold was compared with clinical status of respondents. RESULTS: As the threshold increased from 1% to 10%, the additional yield of clinical asthmatics decreased, indicating a ranking in asthma probability order (all 7 in the top 1% were clinical asthmatics compared with 91% of the top 5% and 83% of the top 10%). Percentages of clinical asthmatics were generally slightly higher than system PPV predictions. CONCLUSIONS: The system ranked the population in asthma probability order and estimated PPV conservatively, enabling health-care providers to predict resource implications of a screening program.

Asthma↗

PubMed2005

Temporal change in the prevalence of respiratory symptoms and obstructive airways disease 1993-2001.

BACKGROUND: There has been little available information regarding secular changes in the prevalence of respiratory symptoms since the mid-1990s. AIM: To examine changes in the prevalence of respiratory symptoms for 1993-2001. DESIGN OF STUDY: A series of postal questionnaire surveys. SETTING: Two general practice populations, including all age groups. METHOD: Four postal respiratory questionnaire surveys were conducted between 1993 and 2001. Subjects who replied to two or more surveys (8058 adults and 2350 children) were included in the main analyses. Validated scoring systems were used to define obstructive airways disease in adults and asthma in children. RESULTS: Over the 8-year observation period there were increases among adults in the crude prevalence of wheeze, being woken by cough, receipt of current asthma medication, and of obstructive airways disease, compared with decreases in children for wheeze, night cough, asthma attacks, and asthma. For adults, adjusted odds ratios per year of secular increase were 1.03 (95% confidence interval [CI] = 1.02 to 1.03) for wheeze, 1.03 (95% CI = 1.02 to 1.03) for being woken by cough, 1.03 (95% CI = 1.02 to 1.04) for asthma medication, and 1.02 (95% CI = 1.01 to 1.03) for obstructive airways disease. These increases were greater in those aged over 44 years, in males, and in those without a family history of asthma or a history of hayfever or eczema. Corresponding decreases for children were 0.94 (95% CI = 0.92 to 0.97) for wheeze, 0.93 (95% CI = 0.91 to 0.96) for night cough, 0.93 (95% CI = 0.90 to 0.95) for asthma attacks and 0.98 (95% CI = 0.95 to 1.00) for asthma. CONCLUSION: The increases found in adults are more likely to be due to chronic obstructive pulmonary disease (COPD) than asthma. This is supported by the decreases in symptom and asthma prevalence in children.

Adolescent↗

PubMed2004

Development of a questionnaire weighted scoring system to target diagnostic examinations for asthma in adults: a modelling study.

BACKGROUND: Identification and treatment of unrecognised asthmatics in the community is important for improving the health of the individual and minimising cost and quality of life burden. It is not practical to offer clinical diagnostic assessment to whole communities, and a simple tool such as a questionnaire is required to identify a smaller target group. Conventional questionnaire screening methods which separate individuals into positive and negative categories have resulted in large numbers of individuals requiring clinical assessment. This study has therefore developed and tested a weighted scoring system that prioritises those most urgently in need, based on their questionnaire responses. METHODS: A stratified random sample of adult respondents to a general practice postal questionnaire survey were categorised 'asthmatic' or 'non-asthmatic' according to three expert physicians' opinions. Based on this categorisation, logistic regression was used to derive weights reflecting the relative importance of each question in predicting asthma, allowing calculation of weighted scores reflecting likelihood of asthma. Respondents scoring higher than a chosen threshold would be offered diagnostic examination. RESULTS: Age and presence of wheeze were most influential (weight 3) and overall weighted scores ranged from -1 to 13. Positive predictive values (PPV) were estimated. For example, setting the threshold score at nine gave an estimated PPV for asthma diagnosis of 93.5%, a threshold score of seven corresponded to PPV 78.8%. PPV estimates were supported by examining 145 individuals from a new survey. CONCLUSION: Weighted scoring of questionnaire responses provides a method for evaluating the priority level of an individual 'at a glance', minimising the resource wastage of examining false positives.

Adolescent↗

PubMed2004

Childhood asthma: healthcare resource utilisation in those with and without a diagnosis of the condition.

AIM: To examine healthcare utilisation and the direct financial costs in providing medical care to a population of children aged 5-15 years with respiratory complaints. Secondarily, to assess whether these costs depended upon having specific asthma diagnosis or not. METHOD: A postal respiratory questionnaire was sent to the parents or guardians of all children registered with two general practices. A search of the general practice medical records over a 2-year reference period was made for a stratified random sample and results are presented for 488 children aged 5-15 years. RESULTS: The cost of primary care lower respiratory tract consultations in children with 4-5 symptoms/risk factors was pounds sterling 17.02 per patient per year for those with a previous diagnosis of asthma compared with pounds sterling 6.08 per patient per year for those with the same number of symptoms but no diagnosis (t = -4.446, P<0.001). The cost of primary care lower respiratory consultations in those with no GP diagnosis of asthma and no symptoms/risk factors was pounds sterling 2.25 per patient per year. CONCLUSIONS: Studies, which fail to include the costs associated with treating children with respiratory symptoms but without a formal diagnosis, will seriously underestimate the costs of treating asthmatic children.

Adolescent↗

PubMed2003

Identification of adults with symptoms suggestive of obstructive airways disease: validation of a postal respiratory questionnaire.

BACKGROUND: Two simples scoring systems for a self-completed postal respiratory questionnaire were developed to identify adults who may have obstructive airways disease. The objective of this study was to validate these scoring systems. METHOD: A two-stage design was used. All adults in two practice populations were sent the questionnaire and a stratified random sample of respondents was selected to undergo full clinical evaluation. Three respiratory physicians reviewed the results of each evaluation. A majority decision was reached as to whether the subject merited a trial of obstructive airways disease medication. This clinical decision was compared with two scoring systems based on the questionnaire in order to determine their positive predictive value, sensitivity and specificity. RESULTS: The PPV (positive predictive value) of the first scoring system was 75.1% (95% CI 68.6-82.3), whilst that of the second system was 82.3% (95% CI 75.9-89.2). The more stringent second system had the greater specificity, 97.1% (95% CI 96.0-98.2) versus 95.3% (95% CI 94.0-96.7), but poorer sensitivity 46.9% (95% CI 33.0-66.8) versus 50.3% (95% CI 35.3-71.6). CONCLUSION: This scoring system based on the number of symptoms/risk factors reported via a postal questionnaire could be used to identify adults who would benefit from a trial of treatment for obstructive airways disease.

Adult↗