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NPLEX II study materials
NPLEX II study resources

NPLEX II: Part II – Core Clinical Science

NPLEX II · Work through your exam, one topic at a time.

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Part II – Core Clinical Science

Domain 2 – Core Clinical Science

Part II – Core Clinical Science tests clinical reasoning and safe application of naturopathic care: history and physical examination, laboratory and imaging selection, and evidence-informed therapeutics across nutrition, botanical medicine, physical medicine, lifestyle, and homeopathy, within appropriate referral boundaries.

Core rules

  • Test performance: sensitivity = TP/(TP+FN); a highly sensitive test is useful for ruling out disease when negative (SnNout). Specificity = TN/(TN+FP); a highly specific test is useful for ruling in disease when positive (SpPin). Positive and negative predictive values change with prevalence; likelihood ratios are more stable.
  • Imaging: choose the least invasive study that answers the question. Ultrasound first for suspected cholelithiasis, thyroid nodules, and DVT; CT for acute abdomen, trauma, and renal colic; MRI for soft-tissue and spinal pathology without red flags; plain films first for most fractures. Avoid ionizing radiation in pregnancy when an alternative exists.
  • Labs: interpret against pretest probability and confirm unexpected results. Recognize pre-analytic error such as hemolysis, fasting status, and improper collection.
  • Therapeutics: screen for interactions. St John's wort induces CYP3A4 and P-glycoprotein, reducing levels of many drugs; ginkgo, garlic, and high-dose fish oil may increase bleeding risk. Do not let a benign modality delay urgent care.

Worked example

A 45-year-old woman has recurrent right upper quadrant pain after fatty meals and a positive Murphy sign, without fever or jaundice. The best initial imaging is RUQ ultrasound: it is sensitive for gallstones, avoids radiation, and can assess wall thickening and pericholecystic fluid. If ultrasound is negative and suspicion remains high, a HIDA scan is the next functional test. CT is not first-line because it is less sensitive for stones and adds radiation. Fever, jaundice, and instability would raise concern for cholangitis and prompt urgent evaluation.

Mark-losing traps

  • Treating predictive values as fixed test properties.
  • Equating a negative result on a low-sensitivity test with absence of disease.
  • Missing drug–herb interactions or attributing symptoms to a supplement without a timeline.
  • Anchoring on a prior naturopathic diagnosis and ignoring red flags.