Top Diagnoses in Primary Care Offices

Margaret A. Fitzgerald, DNP, FNP-BC, NP-C, FAANP, CSP, FAAN, DCC, FNAP

Q I have heard that the diagnoses you will see in primary care practice are quite different from what I see in my work as an RN in an acute care hospital. As a NP student, what should I expect to encounter in my primary care rotations? How should I prepare for the exam and practice given the number of possible diagnoses I could encounter?

A One point that I emphasize in the family NP and adult-gerontology-primary care NP certification review courses is which diagnosis groups are common in family and internal medicine practices. Exam candidates are often thinking of the esoteric, sickest of the sick, such as patients seen in acute care settings, but a relatively small number of common conditions account for the vast majority of diagnoses in the patients you can expect to see daily in primary care practice.

This point is supported by data from the National Ambulatory Medical Care Survey (NAMCS), an ongoing survey conducted by the CDC’s National Center for Health Statistics that gathers descriptive data regarding ambulatory visits in the United States. The top 20 diagnoses for which primary care office visits were made from the 2018 NAMCS survey (the year covered by the most recent NAMCS survey, which predates Covid-19 diagnosis) are shown in Table 1. As you can see, the primary concerns for which patients visit a primary care provider are those that you learned about in your classes and clinical rotations.

Table 1. Patient Visits to Primary Care Offices: Top 20 Diagnoses

Diagnosis* Estimated number of visits in 2018 (in thousands)
1. Essential hypertension 33,610
2. Diabetes mellitus 26,953
3. Osteoarthritis 16,713
4. Depressive disorders, excluding bipolar depression and adjustment reaction with depressed mood 13,133
5. Acute respiratory infections 12,974
6. Retinal detachment and other retinal disorders, diabetic retinopathy 11,181
7. Joint disorders 10,999
8. Cataracts (excluding diabetic cataracts) 10,534
9. Hyperlipidemias 10,049
10. Conditions of the spine and back, excluding low back pain 9,388
11. Attention-deficit hyperactivity disorder 8,684
12. Otitis media and Eustachian tube disorders 8,566
13. Acute pharyngitis 8,331
14. Obstructive sleep apnea and sleep apnea NOS 8,218
15. Glaucoma 8,172
16. Coronary atherosclerosis 7,910
17. Gastroesophageal reflux disease 7,511
18. Acute and chronic sinusiti 7,256
19. Allergic rhinitis 6,984
20. Cardiac dysrhythmias, excluding ventricular fibrillation 5,991

*Diagnoses that were in the 2016 top 20 list but did make the 2018 list include asthma (5,792) and opioid-related disorders (5,704). Data for this table are pre-Covid-19. The current Fitzgerald Review includes COVID-19 clinical information.

Source: National Ambulatory Medical Care Survey: 2018 National Summary Tables.

In 2018 there were approximately 860,386,000 visits to primary care offices. The top five diagnoses—essential hypertension, diabetes mellitus, osteoarthritis, depressive disorders, and acute respiratory infections—accounted for more than one-tenth of these visits. Hypertension, which accounted for more than 33 million visits, is the leading diagnosis for which office visits were made, but respiratory conditions as a group, including infections as well as asthma and allergic rhinitis, accounted for a greater number of visits, with more than 41 million. The top diagnosis groups are shown in Table 2. Nearly one-third of visits were for conditions within the top four diagnosis groups: musculoskeletal and connective tissue, circulatory, respiratory, and mental, behavioral, and neurodevelopmental disorders.

Table 2. Patient Visits to Primary Care Offices: Top 10 Diagnosis Groups with Leading Diagnoses

Diagnosis group Number of visits (% of all visits)*
1. Musculoskeletal and connective tissue
Osteoarthritis, joint disorders, conditions of spine/back (excluding low back pain), low back pain, soft tissue disorders related to use, overuse, and pressure
72,405,000 (8.4)
2. Circulatory
Essential hypertension, coronary atherosclerosis and other chronic ischemic heart disease, heart failure, cardiac dysrhythmias
69,679,000 (8.1)
3. Respiratory
Acute respiratory infections, acute pharyngitis, allergic rhinitis, acute/chronic sinusitis, asthma, acute and chronic bronchitis
58,906,000 (6.8)
4. Mental, behavioral, and neurodevelopmental disorders
Depressive disorders, other mood disorders/nonpsychotic mental disorders/behavioral syndromes, attention-deficit hyperactivity disorders, opioid-related disorders
55,727,000 (6.5)
5. Endocrine, nutritional, and metabolic disease
Diabetes mellitus, dyslipidemia, hypothyroidism, obesity
52,388,000 (6.1)
6. Diseases of the eye and adnexa
Retinal detachment and other retinal disorders/diabetic retinopathy, cataracts, glaucoma, inflammation and disorders of eyelid, conjunctivitis
50,639,000 (5.9)
7. Skin and subcutaneous tissue
Actinic keratosis and other sun-exposure–related disorders, acne, psoriasis, seborrheic keratosis, contact dermatitis and other eczema
43,058,000 (5.0)
8. Genitourinary
Disorders of the breast (excluding unspecified lump or mass), urinary tract infection, disorders of menstruation and abnormal bleeding, benign prostatic hyperplasia, calculus of kidney and ureter
38,855,000 (4.5)
9. Diseases of digestive system
Gastroesophageal reflux disease (with esophagitis), hernias of abdominal cavity, irritable bowel syndrome, anal and rectal diseases
37,234,000 (4.3)
10. Neoplasms
Malignant neoplasm of skin (nonmelanoma), malignant neoplasm of breast, benign neoplasm of skin, malignant neoplasm of prostate
26,308,000 (3.1)

*Total number of visits in 2018 was 860,386,000. Data for this table are pre-Covid-19.

Source: National Ambulatory Medical Care Survey: 2018 National Summary Tables.

These lists should provide some perspective on the task before you as you prepare for the certification exam and practice. My advice is to learn the evaluation, diagnosis, and treatment of these top 20 diagnoses, ensuring that you have a thorough understanding of each. Taking this approach will provide you with a solid foundation of knowledge that will help you succeed on the exam and in your initial year of practice. As a practicing NP, you will build upon this knowledge as you gain practice experience.