key: cord-0682147-f6bie3uv
authors: Granahan, Aoife; Sazali, Hafsah; Tummon, Olga; Costigan, Orla; Fleming, Louise; Moriarty, Blaithin; Lally, Aoife
title: The ‘number needed to treat’ metric: a further marker of the impact of COVID‐19 on malignant melanomas
date: 2022-04-27
journal: Clin Exp Dermatol
DOI: 10.1111/ced.15186
sha: fc822f11b3ffff07b01676cdbb596709dad98723
doc_id: 682147
cord_uid: f6bie3uv

We comment on a previous article, describing the number needed to treat metric as a further marker on the impact of COVID‐19 on treatment of malignant melanomas.[Image: see text]

Dear Editor, We read with interest the recent article published in Clinical and Experimental Dermatology by Bowe et al., 1 describing the impact of the COVID-19 pandemic on malignant melanoma (MM) services in Ireland. We wish to add our experience of the impact of the COVID-19 pandemic on MM services, and to highlight the value of the 'number needed to treat' (NNT) as a metric to further analyse this.

All patients with suspicious pigmented lesions (PL) who were referred electronically [using the National Cancer Control Programme (NCCP) referral form] to dermatology rapid access skin cancer clinics, were identified during 6-month timeframes (March-August) in both 2018 and 2020.

Bowe et al. 1 reported a 27% decline in PL referrals between 2019 and 2020, with continued decline through 2021. Although we observed a 58% decline in PL referrals during the initial containment and lockdown phase of the COVID-19 pandemic in April 2020 compared with similar timeframe in April 2018, 2 we found that, as government restrictions eased, there was a five-fold increase in PL referrals from April (n = 17) to August (n = 89) 2020 ( Fig. 1 ). The total number of referrals received electronically in our institution in 2020 (n = 864) was 27% higher than in 2018 (n = 632). This upward trend in referrals has continued, with total electronic PL referrals received in 2021 (n = 1280) being more than double the total received in 2018 (n = 632) and a third higher than referrals received in 2020. 3 Like In 2018, 23 invasive MMs and 240 benign lesions were diagnosed during the 6-month study period, producing an NNT ratio of 9.6. In 2020, melanoma diagnoses remained stable, but there was a 56% drop in benign lesions, producing an NNT of 4.5 in 2020 ( Table 1 ). The halving of the NNT highlights a pandemic-induced streamlining of dermatology services to focus on delivery of urgent skin cancer care. A low NNT raises concerns regarding potentially missed cases, and may reflect patients' reluctance to attend healthcare services during a period of societal restrictions and concerns regarding infection risk.

We agree with our colleagues, Bowe et al., that continuous evaluation of the impact that the pandemic has had on MM services is critical. We report the value of the NNT metric as an underused tool to assess resource efficiency, diagnostic accuracy and practice standards, which is of particular significance when faced with the challenges of the COVID-19 pandemic. We are concerned by the trends towards later-stage MM at the time of diagnosis, but our experience of continued increased in our PL referrals would suggest that patients in our catchment area are no longer reluctant to access healthcare services as the pandemic seems to be moving to an endemic status. 

The influence of the COVID-19 pandemic on Breslow thickness and outpatient malignant melanoma service provision in an Irish dermatology centre

Decline in pigmented lesion referrals and melanoma diagnoses during COVID-19 lockdown

The National Healthlink Audit Portal Systems eReferrals National Cancer Control Programme (NCCP) Available at

We would like to thank and acknowledge Nicola Moran (Data Manager St Vincent's University Hospital) and Eileen Nolan (National Programme Manager, GP Cancer Electronic Referral Systems, National Cancer Control Programme), for their assistance in providing data for this report. 

the authors declare that they have no conflicts of interest. Ethics approval ethics approval and informed consent were not applicable.

data are available on request from the corresponding author.Aoife Granahan, 1 Hafsah Sazali, 1 Olga Tummon, 1 Orla Costigan, 2 Louise Fleming, 1,3 Blaithin Moriarty 1,2,3 and Aoife Lally 1,2,3