In 1973, the Washington area Blue Cross-Blue Shield health insurance plan offered a moderate level program for families at a cost of $44.99 a month. This year the same plan costs $91.64 a month.

Blue Cross and Blue Shield, the largest insurance program in the Washington metropolitan area - which covers most government workers as well as others who work for themselves or private companies - have increased premiums 35 to 40 per cent in the last year alone.

Two weeks ago, the U.S. Civil Service Commission announced new health insurance rates for plans offered government workers. Many civil servants found that their premiums will go up, starting Jan. 1, 10 to 15 per cent or more.

Policy-holders who seldom use their insurance may suspect that high profits or administrative inefficiencies on the part of the insurance companies account for the increases, but economists who have studied the problem find a less sinister explanation: health insurance premiums have gone up because the cost of medical care has gone up.

Consumers distressed by the cost of medical care can expect little good news in the near future. The cost of medical care will continue to rise and, as a result, the cost of insurance - which increasingly finances medical care in this country - will also increase. The only solution for consumers who want to pay less for health insurance is to assume more of the cost - and more of the risk - themselves.

Some economists now argue that consumers should pay more out of their own pockets, not only to lower the cost of insurance but because, it is argued, insurance itself is one of the culprits behind rising health care costs.

According to this view, the advantage of insurance - that is shields the patient from disastrously high medical costs - is also something of a drawback because insurance also give the illusion that medical are is free.

In an article published last summer in "The Public Interest," Harvard economist Martin Feldstein argued that "increased insurance has induced hospitals to improve their product and provide much more expensive and sophisticated care."

Feldstein went on to describe a vicious circle that made the process self-perpetuating. "The high cost of care," he wrote, "induce families to buy more complete insurance, and the growth of insurance induces the hospital to produce more expensive care."

Since 1950, the percentage of medical expenses paid by insurance programs has grown dramatically in the United States. Consumers paid 68 per cent of their health bill directly in 1950, with private insurance paying 8.5 per cent and public program paying 20.2 per cent, according to figures compiled by the Congressional Budget Office.

Today, consumer spending is estimated to be about 29 per cent, with private health insurance paying 31 per cent and government programs paying 39 per cent.

Economists have recognized for some time that the federal income tax structure subsidizes, or at least encourages, the purchase of health insurance. The tax incentive for health insurance works in two ways. If an individual pays health insurance premiums, half the expense up to a maximum of $150 is deductible on his or her tax return.

If an individual's employer pays some or all of the employee's health insurance premiums the employer can deduct whatever is paid as a cost of doing business. When an employer pays all of an employee's health insurance premium, as many now do, the employee in effect gets more insurance for the same money than if he or she paid the premium, since none of the premium cost is taxable as income to the employee.

But even if the employer pays medical insurance premiums for employees, employees still bear part of the burden in wages diverted to pay health benefits and in higher prices they pay for consumer goods as businesses pass on the higher costs for health insurance to their customers.

The most popular form of health insurance coverage includes either no deductible before the insurance company begins paying bills, or an annual deductible of only $25 to $100, with the patient paying no more than 20 per cent of the total bill after paying the initial deductible.

As an antidote to this situation Feldstein proposed that policy-holders be encouraged to absorb more of the cost of care directly by eliminating tax incentives for insurance plans with low or no deductibles. He also suggested an income-graduated system of deductibles to discourage patients from frivalous or unnecessary use of medical care.

Feldstein's proposal - which has been made previously in other forms and criticized for a variety of reasons - goes to the heart of the insurance system.

Simply put, one reason that insurance premiums are going up is that the people who use the benefits - patients - are the same people who pay premiums to provide money for the benefits. That is the nature of an insurance system - to spread the impact of a financial disaster over a large number of persons. But the costs also are spread over that same group.

An insurance system depends upon large numbers of people paying more in premiums in any given year than they take out in benefits. If people get "their money's worth" - that is, if they get as much or more in benefits than they paid in premiums - the cost of premiums must go up to pay the bills.

In 1975, according to figures supplied by the Health Insurance Institute, private health insurers (excluding Blue Cross and Blue Shield), took in about $19.1 billion in premiums and added another $645 million in income from investments.

Of the $19.7 billion in income, according to the institute, 79.3 per cent was paid out in benefits, 3.7 per cent was added to reserves, leaving 13.4 per cent (after the addition of income investment to premiums) for profits and operating expenses. However, after expense, the institute said, the industry was left with a net loss of 1.1 per cent.

The experience in 1976, according to a spokesman, was slightly different. The industry showed a profit after expenses of .6 of 1 per cent.

Insurance is a hedge against disaster, against an event that would be financially devastating to a policy holder. What has happened to health insurance in this country, according to Feldstein and other economists who share his view, is that it has become a hedge against virtually every relatively low cost eventuality without fully covering against real catastrophits that could bankrupt an individual or family.

Raising the deductible - or the amount that an individual or family.

Raising the deductible - or the amount that an individual or family must pay out of pocket before insurance begins paying bills - can significantly lower premium costs. Aetna Life and Casualty, one of the nation's largest commercial health insurers estimated that a hypothetical group plan for a family of our paying 80 per cent of all medical expenses would cost $1,000 a year with no deductible, and $700 in premiums with a $500 deductible.

Under these hypothetical plans - based on computations of real claims experience by Aetna - a family would save $300 immediately in lower premiums if it had no medical expenses.

If a family with the $500 deductible policy had $500 worth of expenses, the real net cost to the family - compared to what its cost would have been if it had taken the policy with no deductible - would be $100.

With the no deductible policy, the insurance company would pay 80 per cent - or $400 - of a $500 claim.In addition to the $100 out-of-pocket expense, the $300 higher premium must be added, for a net out-of-pocket expense of $400. The individual with a $500 deductible policy, therefore would pay only $100 more. With expenses of $400, the same family would pay only $20 more, and with expenses of $350, the family would save $20.

A reasonably healthy family, according to Aetna associate actuary Frank Frinkenberg, might find the higher deductible "not a bad bet," if it were offered.

Such a plan is not offered, according to insurance company officials, because consumers do not ask for it. The highest deductible offered, when one is offered at all, usually does not exceed $100.

Insurance company officials warn that a larger deductible could be too successful in lowering utilization of medical services. Higher deductibles insurance officials assert, can prevent patients from using medical services when they need them.

A study conducted among members of a prepaid health plan at Stanford University found that use of physician services dropped after patients were required to begin paying 25 per cent of costs out of their own pocket. No systematic, comprehensive study has yet been done, however, to determine whether forcing a patient to pay more of his medical costs has an adverse effect on his health.