Diagnostic spirometry for COPD on the rise

8th June 2023

Diagnostic spirometry is increasingly used to confirm the presence of chronic obstructive pulmonary disease (COPD) but there are still existing barriers to more widespread use, according to a recent analysis.

Published in the journal NPJ Primary Care Respiratory Medicine, Swedish researchers examined whether the proportion of patients with diagnostic spirometry had increased over time. The team originally explored spirometry use in 2005 but re-assessed the level of use following the introduction of national guidelines in 2014. In the current study, they also set out to determine any factors associated with omitted or incorrectly interpreted spirometry.  

Using data from medical reviews and a questionnaire from primary and secondary care patients diagnosed with COPD between 2004 and 2010, the researchers compared the findings from a cohort diagnosed between 2000 and 2003. 

Changes in use of diagnostic spirometry

Among 703 patients with a COPD diagnosis between 2004 and 2010, 88% of these had diagnostic spirometry, compared with 59% (p < 0.001) in the previous cohort. Furthermore, the correct interpretation of spirometry results also increased between the two periods (75% vs 82%; p = 0.010).

In further analysis, it became clear that factors associated with not having diagnostic spirometry were: current smoking (Odds ratio, OR = 2.21, 95% CI 1.36 – 3.60), low educational level (OR = 1.81, 1.09 – 3.02) and being managed in primary care (OR = 2.28, 95% CI 1.02 – 5.14). The authors speculated that the lower use of spirometry in current smokers was largely because physicians probably felt the diagnosis was more likely and hence did not require confirmation.

While greater use of diagnostic spirometry was encouraging, the authors suggested that there was still a need for continuous medical educational activities to increase diagnostic accuracy.

Spirometry in context

The use of diagnostic spirometry has been advocated as a means to identify COPD in those with airflow obstruction and respiratory symptoms. However, spirometry is under-used in practice, with a real-world study finding that data from the technique was only used in 43.5% of nearly 60,000 COPD patients.

In fact, not using diagnostic spirometry potentially means that patients could be either under- or over-diagnosed with the condition. For example, it has been suggested that approximately 70% of COPD worldwide may be under-diagnosed and 30-60% of patients over-diagnosed. 

An inadequate assessment with diagnostic spirometry has important implications for patient management. For example, a late COPD diagnosis, can result in a higher exacerbation rate, increased comorbidities and costs compared with an early diagnosis.

Study investigates anti-rheumatic drug dose and incident retinopathy

28th January 2023

The risk of retinopathy from hydroxychloroquine is less than 10% over 15 years for most patients, with cases generally mild in nature

Hydroxychloroquine-induced vision-threatening retinopathy occurs in only a small proportion of patients over time with the majority of cases of mild severity according to the findings of a long-term cohort study by US and Canadian researchers.

As an anti-rheumatic treatment, hydroxychloroquine provides a survival benefit for patients with autoimmune diseases such as systemic lupus erythematosus. However, a recognised adverse effect of the drug is retinopathy although the summary of product characteristics (SPC) of the drug suggests that this complication is very uncommon, provided that the recommended daily dose is not exceeded. Despite this assertion, there is a lack of data on the incidence of retinopathy associated with longer term use.

In the present study, researchers undertook a cohort study, including patients aged 18 years and older who were prescribed hydroxychloroquine between 2004 and 2020 and who participated in retinal screening. The primary outcome for the study was hydroxychloroquine induced retinopathy. The risk of developing retinopathy was estimated over a 15-year period based on a weight-based dose of the drug, i.e., > 6 mg/kg/day (which is not advised by the SPC), 5 to 6 mg or < 5 mg/kg/day.

Hydroxychloroquine and development of retinopathy

A total of 3,325 individuals with a mean age of 58.2 years (82.7% female) were included and who had used the drug between 2004 and 2014 and then continued for a further 5 years. Overall, 65.4% were given a dose of 5 mg/kg or less and 18.6% received more than 6 mg/kg/day.

Among the entire cohort, 81 individuals developed retinopathy; 56 with mild disease, 17 moderate and 8 severe. The authors calculated a cumulative incidence of retinopathy of 2.5% over 10 years and 8.6% over 15 years.

Among patients prescribed doses in excess of 6 mg/kg/day, the cumulative risk was much higher at 21.6% compared to only 2.7% for a dose of 5 mg/kg/day. In addition, the risk for severe retinopathy at 15 years was only 1.1%.

The authors concluded that the overall risk of hydroxychloroquine retinopathy was 8.6% after 15 years and that most cases were mild, though cautioned that higher doses were associated with a greater incident risk.

Citation
Melles RB et al. Hydroxychloroquine Dose and Risk for Incident Retinopathy : A Cohort Study. Ann Intern Med 2023

Study shows nearly half of hospitalised patients had COVID-19 complications

19th July 2021

Among hospitalised patients, virtually half had COVID-19 complications, and which are likely to impact on future health services.

The mortality rate from infection with COVID-19 is high at approximately 26% and it has also become recognised that COVID-19 complications can occur in a large number of patients. Information on the incidence and type of COVID-19 complications is important for both patients and healthcare providers. For instance, patients need to know the likely time course of any complications whereas healthcare providers require this data to help with resource allocation and long-term planning for the delivery of services. Moreover, a sizeable number of patients with COVID-19 are admitted to intensive care units and while mortality is widely used as an outcome measure in many of the COVID-19 clinical trials, it fails to adequately capture the fact that survivors experience significant morbidity upon discharge.

A better understanding of the range and incidence of COVID-19 complications among those who are critically ill with the virus, is therefore critical to an assessment of the long-term burden on healthcare systems. In an effort to determine the range and prevalence of immediate complications of infection with COVID-19, a team from the Centre for Medical Informatics, Usher Institute, Edinburgh, Scotland, undertook a prospective, multi-centre cohort study in 302 UK which included adults, aged 19 years and older, with confirmed COVID-19 and admitted to hospital. Data was captured upon admission and after days 1, 3 and 9 and at discharge or the patient’s status after 28 days and included demographics and co-morbidities. The team set the primary outcome as the incidence of in-hospital complications and which was defined as organ-specific diagnoses occurring alone or in addition to any hallmarks of COVID-19 illness.

Findings
A total of 75,276 patients were included in the analysis with a mean age of 71.1 years (56% male) and with the majority (73.5%) being of white ethnicity. The existence of one or more comorbidities was present in 81% of participants. and the overall rate of COVID-19 complications was 49.7%. The most common complications reported affected the renal system (24.3%), systemic effects (16.3%), gastrointestinal (10.8%), cardiovascular (12.3%), neurological (4.3%) and respiratory (18.4%). Males aged 60 years and over, suffered the highest rate of complications (54.5%) although COVID-19 complications were common across all demographics. For example, among patients aged 19–29 years and without any comorbidities, 21.1% experienced at least one complication, whereas in those aged 50 years and older, the complications occurred in 51.3% of patients. Interestingly, among patients who survived 28 days from first symptoms to discharge, 44% suffered complications and 26.6% of whom, had a worse ability to self-care than prior to their illness.

In discussing their findings, the authors noted the high level of complications experienced by survivors. The most common were renal and in particular acute kidney injury which is known to be associated with substantial long-term morbidity. They also remarked upon how COVID-19 complications had developed in young and previously healthy individuals and how such complications are known to have a negative impact on long-term morbidity.

Citation
Drake TM et al. Characterisation of in-hospital complications associated with COVID-19 using the ISARIC WHO Clinical Characterisation Protocol UK: a prospective, multicentre cohort study. Lancet 2021.