Welcome to the July/August 2024 chapter newsletter.

CHAPTER NEWS

• Join Us for an Exciting Networking Event at Urban Growler!

• September Book Club (New Time and Place)

• West Metro Medical Writers Social Hour

• Join our AMWA North Central LinkedIn Community!

FEATURE ARTICLES

• AMWA Essential Skills Certificate Course: Thoughts and Observations (Part 5: Statistics)

• Dangling Participles

CHAPTER NEWS

🎉Join Us for an Exciting Networking Event at Urban Growler! 🎉

Attention all chapter members! Mark your calendars for a fantastic evening of networking and fun at the Urban Growler on Saturday, September 21st at 5 pm.

🌟 Event Highlights:

• Icebreaker Bingo: Get to know your fellow AMWA members.

• Taco Bar: Enjoy delicious tacos on us!

• Free Drink: First drink is on the house!

• Special Invite: Chapter members are welcome to bring one non-member friend to join the fun!

Don't miss this opportunity to connect, learn, and unwind in a relaxed setting. We look forward to seeing you there!

Date: Saturday, September 21, 2024; 5:00 PM

Location: Urban Growler, 2325 Endicott St, St Paul, MN 55114

RSVP today and let's make this a night to remember!

September Book Club (New Time and Place)

Our chapter book club will meet at a new time and new place on September 23, 2024. We will meet at the Como Lakeside Pavilion area in Como Park in St Paul (1360 Lexington Parkway North) at 2 pm. In the event of inclement weather or a closed pavilion, we will meet in the restaurant in the pavilion building. The pavilion has 2 parking lots and overlooks Lake Como. It offers a peaceful backdrop and features a pathway around the lake.

We will be discussing When Breath Becomes Air by Paul Kalanithi. The author, a neurosurgeon, wrote When Breath Becomes Air as he was dying from stage 4 metastatic lung cancer. He made the diagnosis himself and managed to gain a short remission, before relapsing. His wife completed and edited the book. It is a short, inspirational story well worth reading.

We will also select books for next year’s meetings, so if you have a title you would like considered, please bring it to the meeting. Alternatively, you can send us the title if you are unable to attend (paulpat@pclink.com).

As always, attendees need not have read the book to participate. In the past, we have had attendees who wanted to find out more about a particular title. Either way, we hope to see you there!

FEATURES

AMWA Essential Skills Certificate Course: Thoughts and Observations (Part 5: Statistics)

By Adam Fix

Part 5 of the AMWA Essential Skills Certificate covers statistics for medical writers. Some professional writers run for the hills at any sight of math more complicated than a Sudoku puzzle, but medical writers know that hard numbers are the backbone of a strong scientific argument.

For my part — having never taken a statistics course despite being a mathematics major back in my college days — I found this section of the course quite useful and instructive. Here are three core concepts:

Standard Deviation (SD)

In a dataset, the SD describes the average distance between each data point and the mean value of the distribution. In other words, it shows how much, on average, each data point differs from the mean. The SD is calculated as follows:

1.     For n data points, calculate the mean by adding all the data points and dividing by n

2.     Subtract the mean from each of the individual data points, square each of those differences, and add up all those squared differences to obtain the sum of squares

3.     Divide the sum of squares by (n-1) to obtain the average squared difference from the mean, also called the variance

4.     Take the square root of the variance to obtain the SD

If all that rigamarole sounds a bit … tedious, you can also make Excel do it. For example, input data into cells A1-A100, type =STDEV(A1:A100) in another cell, and BAM! SD calculated!

ChatGPT could also probably do it, if you ask nicely…

Standard Error of the Mean (SEM)

What’s the difference between the SD and standard error of the mean (SEM)? Both measure variability in data, but they serve different purposes and are used in different contexts.

In a nutshell, the SD represents the spread of individual data points around the mean, whereas the SEM represents the spread of different small sample means around the full dataset mean. Mathematically, the SEM is simply the SD divided by the square root of the sample size. Thus, the larger the sample size, the smaller the SEM.

Confidence Interval (CI)

The main value of the SEM is to calculate the confidence interval (CI). The formula is simple: CI = Mean ± (SEM × 2).

The CI is the range in which we expect the true mean of the dataset to lie 95% of the time. In other words, 95% of all possible sample means will fall within approximately 2 SEMs of the true mean.

As you might guess, narrow confidence intervals are better. The narrower the CI, the more precise your estimates will be. To do this, use a larger sample size. A larger sample size means a smaller SEM, which in turn means a narrower CI.

How Do You Interpret a CI That Overlaps 0?

A CI that includes 0 indicates that you cannot reject the null hypothesis (the hypothesis that there is no effect resulting from the factors being studied). In other words, the true mean could plausibly be 0, and the results are NOT statistically significant.

When this happens, you may consider narrowing your CI by increasing your sample size. It may be possible to narrow the CI enough to exclude 0. However, if your narrowed CI still includes 0, you should conclude that the results are not statistically significant.

Example: Suppose the CI for the difference in mean blood pressure reduction between a treatment group and a control group is (-1, 2.5). Since 0 is within this interval, we cannot conclude that there is a significant difference in blood pressure reduction due to the treatment.

Avoid This Common Misuse of SEM

SEM is often reported instead of the SD because the SEM tends to show less variability in the data. This can be a misuse of the SEM. Let’s investigate.

Because SEM is simply SD divided by the square root of the sample size, SEM is always smaller than SD. Thus, reporting SEM instead of SD will—on first impression—create the appearance of less variability and more precision.

Crucially, however, the SEM does NOT describe the variability of data points. It only shows the precision of the sample mean as an estimate of the true mean. If you are describing variability of individual data points, the SD must be reported, not the SEM.

The Empirical Rule

Also known as the 68-95-99.7 rule, this states that—for normally distributed data (i.e., a bell curve)—certain percentages of data points can be expected to fall within one, two, or three SDs of the mean. More specifically:

• 68.3% of data points will be within one SD of the mean

• 95.4% will be within two SD

• 99.7% will be within three SD

This is a useful guideline for interpreting and forecasting data. However, (as the name suggests) this rule is strictly empirical and cannot replace mathematical analysis of data. Also, don’t forget that this applies ONLY to normally distributed data. Make sure your data form a reasonably bell-shaped curve before using this rule!

Dangling Participles

By Michael Franklin

Most native speakers have an intuitive understanding of their language’s grammar. In English, for example, most people tend to use participles correctly but without knowing what a participle is, let alone what a dangling participle is. By understanding how a participle works grammatically, medical writers can avoid potentially embarrassing mistakes and confidently add variety to their writing style.

Definition of a participle

Participles are verb forms that function as adjectives. Present participles always end in -ing (e.g., the healing wound), and past participles end in -ed (e.g., the injured athlete) or -en (e.g., the swollen joints).

Consider the following examples:

“Bleeding gums may be a sign of gingivitis.”

“Impaired vision is common among people 50 years and older.”

The present participle “bleeding” modifies the noun “gum,” and the past participle “impaired” modifies the noun “vision.”

Even though participles function as adjectives that modify a noun or noun phrase, they still have some of the same features as verbs, such as the capacity to take a direct object:

“Patients discontinuing study treatment were excluded from the analysis.”

The participial phrase “discontinuing study treatment” modifies the noun “patients.” What kind of patients are being described? The ones who are discontinuing study treatment. In this example, “discontinuing” is the participle, and “study treatment” is its direct object.

As illustrated in the above examples, participles can be a single word or a phrase. A single-word participle typically precedes what it modifies (e.g., the experienced clinician). In contrast, a participial phrase usually comes after what it modifies (e.g., the clinician experienced in the management of diabetes); however, a participial phrase can also be moved to the beginning or end of a sentence. This movability is what can lead to a common grammatical error: the dangling participle.

Subject-verb relationship

To understand dangling participles, we need to understand that participles retain another feature of verbs: a subject-verb relationship with the noun or noun phrase they modify.

The subject-verb relationship is key to making sure the participle is combined with an appropriate noun or noun phrase. When writers place a participle or participial phrase next to the noun it modifies, they almost always pair it with a noun that could conceivably be the subject of the verb.

“The defining characteristics of the disease include fatigue and muscle pain.”

The sentence above is semantically clear. “Defining” is a participle describing which characteristics of the disease are referred to: the defining ones. This participle has an embedded subject-verb relationship: the characteristics define the disease.

Similarly, the participial phrase in the following example is linked to an appropriate subject.

“Many people living with HIV prefer treatments that require less frequent administration.”

The sentence above is also semantically clear. The participial phrase “living with HIV” tells us which people the sentence is about. There’s also an embedded subject-verb relationship: people live with HIV.

Movable participles

When writers move a participle or participial phrase away from the noun it modifies, they can accidentally pair it with nonsensical subjects. If the subject of the sentence is not the same as the subject of the participle, then the participle “dangles,” that is, it’s linked to the wrong subject. Here’s an example:

“Having reviewed the patient's history, the diagnosis was clear.”

In the above sentence, the participial phrase "Having reviewed the patient's history" is modifying “the diagnosis.” It’s left dangling because the actual subject is unclear. You can identify a dangling participle by pairing it with the sentence’s subject. In this case, does the following make sense?

“The diagnosis has reviewed the patient's history.”

Of course not. The sentence needs to be revised so that its subject is the same as the participle’s subject:

"Having reviewed the patient's history, the doctor found the diagnosis to be clear."

Now when we pair the participle with the subject, the subject-verb relationship is sensible.

“The doctor has reviewed the patient's history.”

This subject-verb relationship is a useful test to determine if your participial phrases are grammatical and clear.

Past participles

The above examples focus on present participles, but the subject-verb relationship test can also be applied to past participles. That relationship, however, is in the passive voice. To illustrate this, let’s look at a few examples of single-word participles and participial phrases.

“Impaired vision is common among people 50 years and older.”

In this sentence, “vision” is the subject of the participle, but the sentence is in the passive voice. We do not mean “vision impairs.” Rather, we mean “vision is impaired.” The agent of the verb’s action is undefined — that is, what is doing the impairing is undefined.

Past participial phrases work the same way, and sometimes contain the agent of the verb in a prepositional phrase:

“Affected by chronic inflammation, the patient's joints were severely swollen.”

In this example, the subject-verb relationship is sensible. The subject of the sentence, “the patient’s joints,” is also the subject of the past participial phrase, “affected by….”

“The patient’s joints were affected by chronic inflammation.”

Converting this sentence to the active voice gives us the following:

“Chronic inflammation affected the patient’s joints.”

Past participial phrases can also dangle:

“Administered at an incorrect dosage, severe side effects occurred.”

In the above sentence, you can identify the dangling participle by pairing it with the sentence’s subject:

“Severe side effects were administered at an incorrect dosage.”

This sentence fails the subject-verb relationship test. It needs to be revised so that its subject is the same as the participle’s subject:

"Administered at an incorrect dosage, the medication caused severe side effects."

Now when we pair the participle with the subject, the subject-verb relationship is sensible.

“The medication was administered at an incorrect dosage.”

Absolute phrases

There is a grammatical construction that looks like a participial phrase but isn’t. An absolute phrase modifies an entire sentence, instead of an individual noun or noun phrase. Absolute phrases can take several forms, but one form looks just like a participial phrase:

“Patients with PD-L1 expression on tumor cells were twice as likely to respond to treatment than patients without PD-L1 expression on tumor cells, suggesting that PD-L1 expression is predictive of treatment benefit.”

The phrase “suggesting that…” is not a participial phrase. It’s not modifying an individual noun or noun phrase in the sentence. Instead, the subject of the absolute phrase is the idea conveyed by the entire sentence.

I try to avoid absolute phrases in my medical writing. When readers see such a phrase, their first impulse is to try to connect it to the subject of the sentence — a futile effort that impairs comprehension and slows them down. As a writer, you can help readers by replacing the absolute phrase with a new sentence in passages like the one above:

“Patients with PD-L1 expression on tumor cells were twice as likely to respond to treatment than patients without PD-L1 expression on tumor cells. This finding suggests that PD-L1 expression….”

Conclusion

Moving participles or participial phrases to the beginning or end of a sentence can add variety to your writing, but it can also lead to dangling participles. This grammatical error disrupts the flow of information, making it difficult or impossible for readers to identify the intended subject. By understanding the subject-verb relationship inherent in all participles and participial phrases, we can confidently use them and provide explanations to authors or clients as to why one sentence is grammatical and another isn’t.