Whether viewed as defensive plays or potential growth leaders in a market rally, U.S. health-care stocks deserve attention these days.

In the market tribulations of September and October, this group was particularly resilient. That is a good sign because it means informed investors like the sector.

New York-based Value Line Inc. ’s investment survey viewed most of the stocks in the accompanying table as timely. All but two are ranked either a “one” or a “two” out of five in the Value Line system for ranking likely gains in the coming 12 months.

In Standard & Poor’s Corp. ’s industry momentum portfolio outlook, three of the 16 categories are in the health-care sector.

In addition, all stocks in the table have positive grades for earnings and dividend growth in S&P’s ranking system. Their growth ratings are either B+ (average) or A- or A (above average and high, respectively) — levels from which the best returns historically have been obtained.

Having identified the stocks with strongest market prospects and best quality, the table lists several fundamental criteria for each company.

Perhaps key at the moment are two ratios measuring balance-sheet strength. The first is the proportion of equity to assets — the higher the proportion, the stronger the balance sheet. As for the ratio of tangible book value to assets, note the high proportions for Celgene Inc., Genzyme Corp. and Gilead Sciences Inc., particularly.

The second strength measurement is cash on hand — consisting of cash, cash equivalents and short-term investments. The figures are for the latest reported quarters (ended either June 30 or Sept. 30). The per-share dollar figure can be compared with stock prices and book value.

Results for discretionary cash flow — cash flow remaining after capital expenditures and dividend payments (if any) — indicate how well each company has been faring in the latest 12 months. This is a more indicative figure than earnings per share.

As many of these companies are pharmaceutical and biotechnology operations, as opposed to health-care services, the table shows research and development spending per share for the past 12 months.

Compare this number to discretionary cash flow to see how much potential exists for increased spending — and how much of a margin there is to maintain R&D if cash flow diminishes.

Another question that arises is whether goodwill and intangibles are actually worth anything in valuing a company. Some of these firms have huge amounts of goodwill and intangibles on the books. Whether that contributes to financial strength now is a debatable point.

The table shows both book value (shareholders’ equity) per share and tangible book value (equity with goodwill and intangibles deducted).

Finally, there are comparable valuations. The table shows the ratio of stock prices to these key numbers.

Most price/book value ratios are above normal, but for a growing industry — and one that’s, perhaps, recession-resistant — they may be acceptable.

Similarly, price to discretionary cash flow and price to sales ratios are in high ranges. Again, these must be weighed in choosing a portfolio.

Finally, the PEG ratio compares current price/earnings ratios with forecast growth over the next five years. This ratio is not universally loved, but it is worth noting — even by those who do not normally use this ratio. IE