Sentence of the Week

This week's sentence:

The proportion of biopsies that occur because of these false-positive results that are retrospectively deemed unnecessary (that is, the woman did not have cancer) is about 7%; therefore, many more women will undergo unnecessary biopsies under annual screening than biennial screening.

The authors of this week's sentence face a real rhetorical challenge. They're trying to recommend a change in a common medical practice (annual mammograms for women over forty), and they're making this recommendation to an extremely large and diverse audience. How can they do a better job of making their case?

What went right: the clear conclusion

This week's sentence is divided by its semicolon into two parts: evidence first, conclusion last. Kudos to the authors for presenting the conclusion in such a reader-friendly way.

The conclusion has a clear, easy-to-understand subject -- women. Readers anxious to discover what's happening to the women are relieved by the prompt appearance of the verb -- "will undergo" -- and an object -- "unnecessary biopsies." Right away, readers know the conclusion's basic story. So they're ready for the mildly complex modifiers at the end: "under annual screening than biennial screening."

More good news: the conclusion also links back to data about annual and biennial mammograms that appeared a sentence earlier in the authors' report. The authors point out that women who receive annual mammograms end up getting "almost twice" as many false positives as women who receive biennial mammograms.

We'll return to this part of the argument later. But first, let's take a look at the beginning of this week's sentence. This bit intervenes between the data about women who get annual mammograms and the conclusion about women who get biopsies. Readers must understand it if they're to follow the authors' logic.

What went wrong, part 1: the belated verb

Unfortunately, this first part of the sentence is not quite as easy as the conclusion. Like the sentence we featured last week on this site, this one gets cumbersome because its verb is delayed for so long. Readers must struggle with an extremely complicated subject before the verb -- "is" -- makes its appearance.

The proportion of biopsies that occur because of these false-positive results that are retrospectively deemed unnecessary (that is, the woman did not have cancer) is about 7% . . .

The sentence would be much easier if the simpler information at the end appeared at the beginning. Such a revision would be tricky, however, because if all we do is say "seven per cent of biopsies," we won't make much progress in shortening the wait for the verb. We might get stuck squeezing in the long list of modifiers attached to "biopsies."

We need, therefore, a new subject for the sentence. Fortunately one lies near at hand -- women. That's the subject the authors use in their conclusion, and they also use it in an explanatory parenthesis. Since the authors felt the explanatory parenthesis was necessary, why not mention the women a little sooner?

About seven per cent of women will prove cancer-free when they receive biopsies that occur because of these false-positive results; therefore, many more women will undergo unnecessary biopsies under annual screening than biennial screening.

This version will be easier for many readers. It will also allow them to track the character -- women -- that's important in the conclusion.

What went wrong, part 2: the chain of "that" modifiers

Probably we're not done, though. The revision is much easier, but it might not accurately reflect the meaning of the original. That's because the original linked so many modifiers to "biopsies" that it's hard to come up with the answer to the question: "seven per cent of what?"

Let's go back to the original sentence's long subject and try to figure out what it means.

The proportion of biopsies that occur because of these false-positive results that are retrospectively deemed unnecessary . . .

Okay, let's unpack the logic here. We're talking about a group of biopsies. What qualifies a biopsy to be part of this group? The group's qualities are listed in the two "that" clauses:

1. biopsies that occur because of these false-positive results AND

2. biopsies that are retrospectively deemed unnecessary

But wait! Did we get that right? Two questions spring to mind. First, does the second "that" clause really describe "biopsies" or "false positive results?"

1. biopsies that occur because of these false-positive results

2. false-positive results that are retrospectively deemed unnecessary

I'm afraid there's no way to determine the answer to this question. The sentence doesn't make clear how readers are supposed to connect the chain of "that" modifiers.

It's tempting to presume that the second quality (deemed unnecessary) is meant to describe biopsies, because if it does, it seems relevant as a reasonable bit of evidence for the sentence's conclusion. If seven per cent of this group of biopsies is deemed unnecessary, then maybe fewer of these biopsies should be performed. How do you do that? You give fewer mammograms that suggest -- in some cases falsely -- that a biopsy is necessary. Okay, that sounds clear: readers may debate it, but it's understandable enough to debate.

But this is not what the sentence actually says, which brings us to our second question: did the authors really mean for the first quality (biopsies that occur because of these false-positive results) to be there at all? Think about the implications if we're talking about seven per cent of those biopsies:

IF: Seven per cent of women prove cancer-free when they receive biopsies that occur because of these false-positive results

THEN: Ninety-three per cent of women prove to have cancer when they receive biopsies that occur because of these false-positive results.

This is just plain puzzling. If a hundred women get a false-positive result on a mammogram -- that is, the mammogram indicates the presence of a phantom cancer when no cancer is there -- then how is it that ninety-three of these women prove to have cancer after all?

If these ninety-three women (of a hundred!) really do have cancer, how does this lead to the conclusion that the false-positive result was in fact false, or that even if it was false, it was a bad thing? If one of these women were, say, me, I wouldn't be chiding the doctor for giving me an unreliable test. I'd be thanking my lucky stars for the happy coincidence that found my cancer before I lay in my grave. If sacrificing a goat led to such reliable results, I'd be clamoring for goat sacrifice to be taught in medical schools. I'd bring the goat to the hospital myself.

The authors are experts in their field, and it's hard for someone outside that field to judge whether they ended up saying something that they simply did not mean. In the face of such a baffling argument, however, it seems reasonable at least to entertain this possibility. So. Assuming for the sake of argument that the sentence doesn't mean what it says, how can it be clarified?

The authors may have gotten into trouble because they wanted to take every possible opportunity to remind readers that mammograms sometimes produce a false-positive result. A second revision could incorporate this reminder without getting enmeshed in a logical tangle:

These false-positive results on mammograms can and do lead to unnecessary biopsies. 7% of women who receive biopsies prove to be cancer free; therefore, many more women will undergo unnecessary biopsies under annual screening than biennial screening.

We can make this revision even more precise by incorporating information from earlier in the paragraph about the women's ages and about the different statistics for annual and biennial screening. In the original, the paragraph's argument was interrupted by the confusing first part of this week's sentence. Now we can show what the argument would look like if it flowed more smoothly from one sentence to the next:

When women between the ages of forty and sixty-nine receive annual mammograms, they get almost twice as many false-positive results as they would if they received mammograms biennially. These false-positive results can and do lead to unnecessary biopsies. When women in this age group get a positive result on an annual mammogram and then get a biopsy, 7% of them prove to be cancer free. Thus many more women will undergo unnecessary biopsies under annual screening than biennial screening.

We can't, of course, be sure that this revision is correct, because it does change the original sentence's meaning. In other words, the original sentence left readers to guess. Unfortunately it left them to guess about one of the primary pieces of evidence for its conclusion. This ambiguity can't help the authors make their case.

What went wrong, part 3: a missing statistic

We're still left with one final question: do we really have the right subject for our most crucial verb? To write our first revision, we used the original sentence's figure of seven per cent. But if seven per cent of these biopsies were deemed unnecessary, then that means that ninety-three per cent of them were necessary. Thus our revision could easily be rewritten one more time:

When women between the ages of forty and sixty-nine receive annual mammograms, they get almost twice as many false-positive results as they would if they received mammograms biennially. These false-positive results can and do lead to unnecessary biopsies. When women in this age group get a positive result on an annual mammogram and then get a biopsy, 93% of them prove to have cancer. But the other 7% prove to be cancer free. Therefore, many more women will undergo unnecessary biopsies under annual screening than biennial screening.

The advantage of this revision? It allows readers to understand both the harms and benefits of the medical procedure in question -- something the authors state elsewhere is the intention of their report:

The decision to start regular, biennial screening mammography before the age of 50 years should be an individual one and take patient context into account, including the patient's values regarding specific benefits and harms.

Hurray for individual choice and informed decisions! But to enable each patient to evaluate benefits and harms for herself, it would help if the authors clearly stated the benefits as well as the harms. In the case of this sentence, a simple revision can put the benefits and harms side by side, where they can be more easily compared.

It may be, of course, that the math is a little more complicated than this final revision suggests. It may be that in addition to the seven per cent of biopsies that are deemed unnecessary, an unknown number of the biopsies are inconclusive. Thus perhaps fewer than ninety-three per cent of the biopsies reveal the presence of cancer.

But if that's the case, once again, the sentence should say so. Like many medical experts who face similar rhetorical challenges, the authors are writing about a subject of deep concern to millions of patients. These patients are entirely dependent upon experts to provide them with a complete and accurate report of the medical evidence. Unless the report is clear, that won't happen, and patients will be left in the dark.

Do you have a candidate for sentence of the week?

If so, submit it to writing-program@uchicago.edu.   Sentences must be from published, professional prose (sorry, no poetry).  You must include a complete citation with your entry. If we use a sentence, we will thank you publicly (if you wish) or privately (if that's what you'd prefer), and we will also reward you with gratitude, kind thoughts, and good karma.  If a sentence is good, we will reveal the name of the author on the site; if a sentence is bad, we will gracefully conceal the author's identity, telling only a few dozen of our closest friends and relations, as well as anyone else who asks nicely. All others are encouraged to try googling the sentence, which usually returns an answer faster than we do.

Bad sentences written by University of Chicago faculty, staff, or students are not eligible, since we assume that such persons write bad sentences only while under the influence of some occult force. Apart from this trivial and unimportant restriction, we welcome sentences, bad and good, by any author whatever, regardless of academic discipline or political affiliation.

If you are interested in structural features common to many academic sentences that seem cumbersome to readers, you may wish to visit the Academic Sentence Generator.