A review of care home ratings shows that care in the South East and North West is the most likely to be of poor quality, compared with the rest of England.
West Yorkshire replaced the Isle of Wight as the worst county in 2016, with 34 per cent of services failing to meet good standards.
Researchers from the firm TrustedCare.co.uk analysed Care Quality Commission (CQC) data and found the proportion of services rated good or outstanding has fallen by nine per cent to date in 2016 compared with 2015.
Over the same period, care home prices jumped by an average of 23 per cent, from £557.86 to 686.32 per week, separate figures suggest.
The analysis found that Herefordshire remains the best county for care services overall, with 92 per cent of providers meeting national standards.
This was followed by Worcestershire and Northamptonshire.
In Staffordshire, only 71 per cent were doing well, while the figure was 69 per cent in Greater Manchester.
The research also found widespread regional variation when it comes to the quality of care homes, nursing homes and care provided in the home.
Some regions performed well in one area but not others.
Durham was found to be the most expensive area for care homes, with average prices there almost doubling in a year from £491.70 per week to £907.
Mark Walford, chief executive of TrustedCare.co.uk, said: “The data shows once more that there is a complex mix of factors that affect the quality and cost of care, and that there isn’t a strong correlation between areas of affluence and local care quality as one might expect, despite a strong link to price of care.
“Instead, factors such as local employment markets, local authority commissioning rates and the level of co-operation between local NHS and social care teams are sure to play into the mix.”
The CQC disputed the figures but said over a quarter of services are rated as requires improvement and a further two per cent are inadequate.
Andrea Sutcliffe, CQC’s chief inspector of adult social care, added: “The first port of call for people looking for information about care should be CQC and the interactive map we launched in October makes it easier than ever before to find information about individual services.
“I would also urge people to share their experiences of care – both good and bad – with us as this information helps to determine the timing and focus of our inspections.”