Patients are waiting longer for access to some key services with "systemic" declines in performance, a think- tank report has warned.
Even England's top hospitals have seen decreases in performance, while those at the bottom end have seen a "marked deterioration", according to an assessment by the Nuffield Trust which advises the Government on healthcare.
Accident and emergency (A&E) patients have often had to wait longer than the four-hour target, according to analysis of how all 156 hospital trusts in England have performed against six national targets over the course of this Parliament.
The report found that the majority of hospitals breached a target on at least one of the six measures - usually the A&E waiting time, the 18-week target for a hospital bed, or the six-week target for scans and other diagnostic tests.
Co-author Holly Dorning said: "The vast majority of patients are still receiving care within the target times, but our analysis shows that deteriorating access to services is starting to affect patients attending even the best-performing hospitals.
"We've known that hospitals have been struggling to meet the four-hour A&E target for a while.
"But the fact that we are starting to see problems in other areas, like access to planned treatment, is a real concern. As this study makes clear, warning lights are now starting to flash across the wider hospital system."
The Nuffield Trust's analysis also questions the assumption that access to care deteriorates as hospitals are asked to treat more patients.
While extra activity in A&E, outpatient treatments and cancer care is matched with poorer performance against access targets, the NHS has absorbed an additional 240,000 diagnostic tests and an additional 45,000 urgent cancer referrals in the past year with little impact on performance against the associated targets.
Criteria monitored by the trust also included the 18-week target for an outpatient appointment, the two-week target for urgent cancer referral, and the 31-day target for cancer treatment.
Co-author Ian Blunt said there could be no "quick fixes" to the problems.
He said: "While looking at a narrow set of targets can only tell us so much about the quality of care, this analysis does suggest that some of the recent reductions in performance are systemic.
"The response to declining performance must be dictated by a deeper understanding of its causes, and political leaders should be aware of their system-wide nature.
"There are no quick fixes for growing waiting times and we need to be prepared to see further breaches of targets in the future."
The report states that l onger waiting times could simply be the result of hospitals having to carry out more procedures. Nuffield Trust analysis shows that increases in hospital activity are not always associated with a decrease in waiting time performance.
The report adds: "Failure to meet, for example, the four-hour A&E target appears to have very little bearing on performance against other measures. This again suggests that these problems may be systemic and that applying extra pressure at hospital level is not the best approach to reversing the recent performance drop."
A Department of Health spokesman said: "The NHS is busier than ever, as innovative treatments and medicines mean people are living longer with complex conditions like heart disease or diabetes.
"We've increased the NHS budget by £16 billion over this Parliament but ultimately we want to reduce pressure on services through our plans to increase access to primary care and look after people better in the community."