One in eight of all adults over 50 had an operation or hospital treatment cancelled last year, with cancer procedures among the most affected, a study has found.
For those suffering from two or more existing medical conditions, the rate rose to one in five.
Researchers at University College London (UCL) also found that diagnoses for arthritis, chronic lung disease, diabetes and hypertension increased in the second half of 2020. They said this could be a consequence of inactivity caused by lockdown.
Of the 623 adults in the survey who had had operations or treatments cancelled between March and December last year, nearly half were still waiting for their hospital appointment to be rescheduled in November and December.
Diagnosis rates for dementia dropped from 9.09 per 1,000 adults pre-Covid to 4.53 per 1,000 adults in June and July last year and to 3.58 adults per 1,000 in November and December.
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Dr Paola Zaninotto, who led the study at UCL’s department of epidemiology and public health, said: "Our study shows that access to health and social care services during lockdown may have disproportionately affected older people and those with multiple medical conditions.
"We found that the rates of diagnoses of new health conditions during the pandemic in the second half of 2020 were substantially higher from the pre-pandemic rates reported in 2018 to 2019."
"The increased isolation during lockdown may have meant that cognitive decline went unnoticed by friends and relatives, or barriers to accessing healthcare may have been experienced more by those with early dementia.
"Conversely, other conditions were diagnosed more frequently than before the pandemic, including arthritis, chronic lung disease, diabetes and hypertension.
"Again, the reasons for these increases are not clear, but fewer opportunities for physical activity and social interaction may have played a part."