Lack of long-term effects from a pedagogical intervention upon blood pressure control—a randomized primary care study

Figures & data

Figure 1. The front of the BP card.

Figure 2. Information on the back of the BP card.

Table I. Data of the pilot study.

Data at inclusion			BP values and results of pilot intervention
	Pilot-I	Pilot-C			Pilot-I	Pilot-C
	n = 56	n = 54	Systolic BP mmHg (95% CI)	at study start	172 (167–176)	171 (166–176)
Age (years) mean (min–max)	61 (35–86)	61 (26–83)		at study end	156 (150–162)	163 (155–170)
Sex (% of group women/men)	67/33	54/46		BP difference	15 (9–22)	8.5 (2.5–15)	p = 0.015
Systolic BP (95% CI) (mmHg)	174 (169–178)	168 (164–172)		p value	< 0.001	0.011
Diastolic BP (95% CI) (mmHg)	96 (93–99)	95 (92–97)
Mean TBP (mmHg) and mean values of group in percent of total of three target levels [140/90, 150/90, 160/90]	147/90 [48, 37, 15]	146/90 [57, 29, 14]	Diastolic BP mmHg (95% CI)	at study start	94 (92–97)	95(92–98)
Mean difference in actual systolic BP and TBP mean (95% CI) (mmHg)	26 (23–30)	23 (19–26)		at study end	88 (85–91)	92(88–95)
Mean difference in actual diastolic BP and TBP (95% CI) (mmHg)	5.9 (3.1–8.8)	4.6 (2.0–7.3)		BP difference	6.5 (2.9–10)	3.2 (−0.5–6.9)	p = 0.021
Mean amount of prescribed antihypertensive drugs (95% CI)	1.6 (1.3–1.8)	1.4 (1.2–1.6)		p value	< 0.001	n.s.
Percent of 0,1,2,3,4 and 5 drugs in study group	(4, 56, 30, 9, 2, 0)	(4, 49, 35, 10, 2, 0)
Percent of patients not treated at inclusion in group	43	33	Percent of patients achieving TBP	37	20	P < 0.05

Table II. Comparative data at inclusion in main study (intervention groups I and IN and controls).

	I	IN	C
	n = 57	n = 59	n = 50
Age (years) mean (min–max)	66 (46–89)	65 (42–92)	62 (46–85)
Sex (% of group women/men)	56/44	51/49	46/54
Systolic BP (95% CI) (mmHg)	165 (161–169)	168 (164–173)	165 (160–169)
Diastolic BP (95% CI) (mmHg)	89 (86–92)	93 (91–95)	93 (90–96)
Mean TBP (mmHg) and mean values of group in percent of total of three target levels [130/80, 140/90, 150/90]	140/88 [23, 58, 19]	139/88 [26, 59,15]	139/88 [24, 66, 10]
Mean difference in actual systolic BP and TBP mean (95% CI) (mmHg)	25 (21–30)	29 (25–34)	26 (22–30)
Mean difference in actual diastolic BP and TBP (95% CI) (mmHg)	1.0 (− 2.0–3.9)	5.4 (3.2–7.7)	5.2 (1.7–8.7)
Mean amount of prescribed antihypertensive drugs (95% CI)	1.7 (1.4–1.9)	1.4 (1.3–1.6)	1.5 (1.3–1.7)
Percent of 0,1,2,3,4 and 5 drugs in study group	(0, 47, 32, 11, 2, 2)	(0, 60, 26, 5, 2, 0)	(0, 50, 30, 2, 2, 0)
Percent of patients not treated at inclusion in group	21	36	36

Table III. Primary effect variables. BP and BP differences before and after intervention and percentage reaching TBP in main study in intervention and control groups.

		Main study
		I	IN	C
Systolic BP mmHg (95% CI)	at study start	165 (161–169)	169 (164–173)	165 (160–170)	n.s.
	at study end	140 (135–145)	140 (133–145)	139 (134–144)	n.s.
	BP difference	25.2 (20.3–30.0)	29.0 (21.9–36.0)	25.8 (19.7–31.9)	n.s.
	p value	p < 0.001	p < 0.001	p < 0.001
Diastolic BP mmHg (95% CI)	at study start	88.9 (85.9–91.8)	93.1 (90.7–95.6)	92.6 (89.1–96.2)	n.s.
	at study end	79.7 (77.2–82.1)	84.3 (81.5–87.0)	82.7 (80.3–85.1)	p = 0.03 (I vs. IN)
	BP difference	9.2 (5.9–12.5)	8.9 (5.9–11.9)	10.0 (5.8–14.1)	n.s.
	p value	p < 0.001	p < 0.001	p < 0.001
Percent of patients achieving TBP		58	40	50	I vs. C p = 0.09 IN vs. C p < 0.05 IN vs. I p < 0.01

Table IV. Drug prescription and treatment-related health care contacts during study period in control and intervention groups.

	Extended study
	I	IN	C	p value
Percent of patients with changes in drug prescription	54	53	42	n.s.*, 0.07* IN vs. C
Mean amount of antihypertensive drugs per patient at study start (95% CI)	1.67 (1.42–1.91)	1.44 (1.26–1.62)	1.46 (1.28–1.65)	n.s.^a
Mean amount of antihypertensive drugs per patient at study end (95% CI)	1.80^n.s. (1.56–2.04)	1.66^b (1.43–1.90)	1.74^b (1.51–1.97)	n.s.^a
Amount of contacts with the nurse mean (95% CI)	5.4 (4.0–6.9)	7.0 (5.6–8.5)	4.1 (2.6–5.4)	0.009^c IN vs. C
Amount of visits to the doctor mean (95% CI)	2.0 (1.5–2.5)	1.5 (1.1–1.9)	2.4 (1.5–3.3)	0.09^c IN vs. C
Amount of telephone contacts with the doctor mean (95% CI)	1.6 (1.1–2.1)	1.3 (0.9–1.7)	1.1 (0.8–1.5)	n.s.^a
Time spent by doctor for intervention (min) (95% CI)	10.6 (9.1–12.1)	10.3 (8.8–11.9)	n.a.

*Chi-square test.

^aANOVA and Tukeys HSD-test.

^bStatistically significantly changed start vs. end, p < 0.05.

^cKruskal–Wallis test with multiple comparisons.

n.s = not significantly different.