Sales promotion by wholesalers affects general practitioners’ prescription behaviours in Japan

Figures & data

Table 1. Descriptive statistics related to MS influence on doctor prescription decisions.

	New Volume			Same Volume			Additional Volume
	Total	(MR co-visits)	(No MR co-visits)	Total	(MR co-visits)	(No MR co-visits)	Total	(MR co-visits)	(No MR co-visits)
Antidiabetic agents	742	698	44	5,996	5,218	778	1,421	932	489
Antihypertensive agents	453	401	52	6,132	5,087	1,045	1,306	921	385
Allergic drugs	260	213	47	3,963	3,213	750	775	505	270
Agents affecting metabolism	306	247	59	3,400	2,893	507	610	401	209
Peptic ulcer agents	122	77	45	2,489	1,879	610	495	320	175
Hyperlipidemia agents	150	123	27	2,358	1,835	523	559	386	173
Central nervous system agents	184	158	26	2,003	1,633	370	424	305	119
Ophthalmic agents	243	195	48	1,973	1,590	383	365	234	131
Respiratory agents	199	189	10	1,382	1,198	184	387	269	118
Vaccines	141	89	52	1,610	1,101	509	179	103	76
Total	5,527	4,595	932	56,799	44,508	12,291	11,255	7,410	3,845

Note: ‘New volume’ indicates that a doctor prescribed a new drug, ‘Same volume’ indicates that a prescribing doctor continued the use of a drug at the same prescription volume, ‘Increasing volume’ indicates that a prescribing doctor increased the prescription volume of a drug, while ‘Decreasing volume’ indicates that a prescribing doctor decreased the prescription volume. ‘MR co-visit’ indicates that MR and MS jointly visited a prescribing doctor, while ‘No MR co-visits’ indicates only MS visited a prescribing doctor. Therapeutic categories were based on the MHLW classification.

Table 2. Doctors’ responses to MS calls related to new prescriptions.

		MS influence on doctor’s prescription behavior
		Strongly influenced		Influenced		Not influenced		Total
MR co-visit	MR visit	1,298	(28.2%)	2,457	(53.5%)	840	(18.3%)	4,595	(100.0%)
	No MR co-visit	179	(19.2%)	491	(52.7%)	262	(28.1%)	932	(100.0%)
	Total	1,477	(26.7%)	2,948	(53.3%)	1,102	(19.9%)	5,527	(100.0%)
χ^2 = 61.3543, p-value <0.000, Gamma = 0.2357, p-value <0.0000
MR influence on doctor’s prescription	Strongly influenced	867	(55.4%)	537	(34.3%)	161	(10.3%)	1,565	(100.0%)
	Influenced	347	(14.8%)	1,673	(71.3%)	327	(13.9%)	2,347	(100.0%)
	Not influenced	84	(12.3%)	247	(36.2%)	352	(51.5%)	683	(100.0%)
	Total	1,298	(28.2%)	2,457	(53.5%)	840	(18.3%)	4,595	(100.0%)
χ^2 = 1397.6459, p-value <0.000, Gamma = 0.5981, p-value <0.0000

Note: ‘New volume’ indicates that a doctor prescribed a new drug, ‘Same volume’ indicates that a prescribing doctor continued the use of a drug at the same prescription volume, ‘Increasing volume’ indicates that a prescribing doctor increased the prescription volume of a drug, while ‘Decreasing volume’ indicates that a prescribing doctor decreased the prescription volume. ‘MR co-visit’ indicates that MR and MS jointly visited a prescribing doctor, while ‘No MR co-visits’ indicates only MS visited a prescribing doctor. Therapeutic categories were based on the MHLW classification.

Table 3. Doctors’ responses to MS calls for the maintaining prescription volume.

		MS influence on doctor’s prescription behavior
		Strongly influenced		Influenced		Not influenced		Total
MR co-visit	MR visit	4,054	(9.1%)	20,644	(46.4%)	19,810	(44.5%)	44,508	(100.0%)
	No MR co-visit	375	(3.1%)	3,544	(28.8%)	8,372	(68.1%)	12,291	(100.0%)
	Total	4,429	(7.8%)	24,188	(42.6%)	28,182	(49.6%)	56,799	(100.0%)
χ^2 = 2231.3729, p-value <0.000, Gamma = 0.4429, p-value <0.0000
MR influence on doctor’s prescription	Strongly influenced	2,492	(44.5%)	2,200	(39.3%)	905	(16.2%)	5,597	(100.0%)
	Influenced	1,288	(5.7%)	16,131	(70.9%)	5,327	(23.4%)	22,746	(100.0%)
	Not influenced	274	(1.7%)	2,313	(14.3%)	13,578	(84.0%)	16,165	(100.0%)
	Total	4,054	(9.1%)	20,644	(46.4%)	19,810	(44.5%)	44,508	(100.0%)
χ^2 = 24,552.7399, p-value <0.000, Gamma = 0.8080, p-value <0.0000

Note: ‘New volume’ indicates that a doctor prescribed a new drug, ‘Same volume’ indicates that a prescribing doctor continued the use of a drug at the same prescription volume, ‘Increasing volume’ indicates that a prescribing doctor increased the prescription volume of a drug, while ‘Decreasing volume’ indicates that a prescribing doctor decreased the prescription volume. ‘MR co-visit’ indicates that MR and MS jointly visited a prescribing doctor, while ‘No MR co-visits’ indicates only MS visited a prescribing doctor. Therapeutic categories were based on the MHLW classification.

Table 4. Doctors’ responses to MS calls for increasing prescription volume.

		MS influence on doctor’s prescription behavior
		Strongly influenced		Influenced		Not influenced		Total
MR co-visit	MR visit	2,652	(26.4%)	5,673	(56.4%)	1,737	(17.3%)	10,062	(100.0%)
	No MR co-visit	179	(15.0%)	585	(49.0%)	429	(36.0%)	1,193	(100.0%)
	Total	2,831	(25.2%)	6,258	(55.6%)	2,166	(19.2%)	11,255	(100.0%)
χ^2 = 258.7246, p-value <0.000, Gamma = 0.3724, p-value <0.0000
MR influence on doctor’s prescription	Strongly influenced	1,909	(50.8%)	1,473	(39.2%)	374	(10.0%)	3,756	(100.0%)
	Influenced	630	(12.2%)	3,799	(73.5%)	742	(14.3%)	5,171	(100.0%)
	Not influenced	113	(10.0%)	401	(35.3%)	621	(54.7%)	1,135	(100.0%)
	Total	2,652	(26.4%)	5,673	(56.4%)	1,737	(17.3%)	10,062	(100.0%)
χ^2 = 2980.09, p-value <0.000, Gamma = 0.6127, p-value <0.0000

Note: ‘New volume’ indicates that a doctor prescribed a new drug, ‘Same volume’ indicates that a prescribing doctor continued the use of a drug at the same prescription volume, ‘Increasing volume’ indicates that a prescribing doctor increased the prescription volume of a drug, while ‘Decreasing volume’ indicates that a prescribing doctor decreased the prescription volume. ‘MR co-visit’ indicates that MR and MS jointly visited a prescribing doctor, while ‘No MR co-visits’ indicates only MS visited a prescribing doctor. Therapeutic categories were based on the MHLW classification.

Table 5. Doctors’ responses to MS calls for decreasing prescription volume.

		MS influence on doctor’s prescription behavior
		Strongly influenced		Influenced		Not influenced		Total
MR co-visit	MR visit	94	(14.8%)	197	(31.1%)	343	(54.1%)	634	(100.0%)
	No MR co-visit	27	(8.0%)	74	(21.9%)	237	(70.1%)	338	(100.0%)
	Total	121	(12.4%)	271	(27.9%)	580	(59.7%)	972	(100.0%)
χ^2 = 206.5739, p-value <0.000, Gamma = 0.8208, p-value <0.0000
MR influence on doctor’s prescription	Strongly influenced	59	(53.6%)	31	(28.2%)	20	(18.2%)	110	(100.0%)
	Influenced	23	(10.3%)	130	(58.3%)	70	(31.4%)	223	(100.0%)
	Not influenced	12	(4.0%)	36	(12.0%)	253	(84.1%)	301	(100.0%)
	Total	94	(14.8%)	197	(31.1%)	343	(54.1%)	634	(100.0%)
χ^2 = 76.6083, p-value <0.000, Gamma = 0.5106, p-value <0.0000

Note: ‘New volume’ indicates that a doctor prescribed a new drug, ‘Same volume’ indicates that a prescribing doctor continued the use of a drug at the same prescription volume, ‘Increasing volume’ indicates that a prescribing doctor increased the prescription volume of a drug, while ‘Decreasing volume’ indicates that a prescribing doctor decreased the prescription volume. ‘MR co-visit’ indicates that MR and MS jointly visited a prescribing doctor, while ‘No MR co-visits’ indicates only MS visited a prescribing doctor. Therapeutic categories were based on the MHLW classification.

Table 6. Doctors’ responses to MS calls by therapeutic category.

	New volume				Same volume				Increasing volume				Decreasing volume
	No MR co-visits		With MR co-visits		No MR co-visits		With MR co-visits		No MR co-visits		With MR co-visits		No MR co-visits		With MR co-visits
	X^2	Gamma	X^2	Gamma	X^2	Gamma	X^2	Gamma	X^2	Gamma	X^2	Gamma	X^2	Gamma	X^2	Gamma
Antidiabetic agents	0.5733	−0.0032	226.3749**	0.6916**	166.6594**	0.4480**	2668.1862***	0.7866***	8.0797*	0.2326**	308.1918***	0.5356***	4.9093*	0.5471**	27.439***	0.7136***
Antihypertensive agents	9.1473**	0.3236**	136.1035**	0.6618**	213.7001**	0.4533**	2703.0455***	0.8223***	17.324**	0.2976**	452.1431***	0.6839***	5.3677*	0.4119**	81.2795***	0.8454***
Allergic agents	2.6860	0.2029	94.9541**	0.6759**	81.3948**	0.3422**	2047.0722***	0.8315***	21.8989**	0.3479**	248.8388***	0.6675***	3.5657	0.3939	25.7526***	0.8454***
Agents affecting metabolism	34.9321***	0.7850***	51.7872**	0.4656**	66.9419**	0.3625**	1696.7171***	0.8329***	20.1645**	0.5609**	176.8106***	0.6229***	0.1827	0.0558	17.5192***	0.6098*
Peptic ulcer agents	18.6140***	0.7487***	24.9976**	0.4177*	115.7451**	0.4611**	1084.2496***	0.8301***	24.0946**	0.5567**	195.2998***	0.6971***	2.2425	0.4809	16.424***	0.9434***
Hyperlipimedia agents	8.5074**	0.4369**	35.3637**	0.3572*	111.7896**	0.4888**	1008.7170***	0.8218***	1.525	0.1533	170.7518***	0.6616***	2.0447	0.3265	17.8462***	1.0000***
Central nervous system agents	6.2463**	0.2902*	57.7373**	0.6745**	67.9338**	0.4274**	923.4184***	0.8116***	21.1672**	0.6202**	92.1107***	0.5892***	3.1924	0.4085	11.3467**	0.8103***
Ophthalmic agents	2.2463	0.1874	11.1424*	0.1132	40.964**	0.3723**	707.9169***	0.7712***	11.3969**	0.0727	47.1062***	0.4472***	1.7912	0.2000	6.3400	0.4937**
Respitatory agents	5.1625*	0.3638	38.1671**	0.6145**	40.5369**	0.4540**	489.8366***	0.7273***	3.8965	0.0491	126.1975***	0.6732***	0.5091	0.0357	6.5625	0.625*
Vaccines	4.8406*	0.1718	54.0001**	0.6118**	35.6923**	0.2900**	715.9562***	0.8510***	2.4038	0.1029	46.6289***	0.5581***	4.4339	−0.600**	13.4844***	0.8387**

Note: ‘New volume’ indicates that a doctor prescribed a new drug, ‘Same volume’ indicates that a prescribing doctor continued the use of a drug at the same prescription volume, ‘Increasing volume’ indicates that a prescribing doctor increased the prescription volume of a drug, while ‘Decreasing volume’ indicates that a prescribing doctor decreased the prescription volume. ‘MR co-visit’ indicates that MR and MS jointly visited a prescribing doctor, while ‘No MR co-visits’ indicates only MS visited a prescribing doctor. Therapeutic categories were based on the MHLW classification.

*: p-value <0.1, **: p-value <0.05, ***: p-value <0.001